By sub01

I was beside myself with anticipation as Carol and my sister slipped off the bed and came to me.  Even untying me became a tease for them.  They played their fingers over my body, stroking my nakedness as one by one they unclipped my arms and legs, then unfastened the cuffs.  This time Carol kept her breasts tantalizing out of my reach.  When I was free she pulled the panties out of my mouth and helped me to stand, but she didn't take off my collar.

"Put these away," Carol told my sister as she handed her the cuffs and panties.  "I think we'll leave your brother's collar on though.  It makes you two look like such a cute little matching pair."  As Mary moved to put the cuffs away, Carol smiled wickedly and moved close to me.  I stood frozen, not sure how I was expected to act.  Did I wait obediently for her to instruct me?  Was she simply teasing me again?  Or did she expect me to embrace her now, take her to the bed... maybe even fuck her?  Carol answered the question for me.  She pressed up against me and slipped her arms around my waist, her large, luscious breasts flattening against my chest.

Carol was a couple inches shorter than me and now we made for a perfect fit as she tilted her head up and kissed me on the lips.  I wasn't quite prepared for the embrace or the kiss and now I felt my cock swell, trapped between our naked bodies.  I couldn't help but slip my arms around Carol's slender waist, returning the embrace.  Oh, how good she felt in my arms!  How warm and slim and fit, her breasts so full and luxurious against my chest!  I slipped my hands down to feel her tight bottom, and as I did she dug her fingers into my back, hurting me gently with her fingernails.

"Ow!" I gasped into her mouth.

"Like that?"

Surprisingly, I did.  She dug her fingers in again, at the same time biting gently on my lower lip.

"Oww!"  My cock throbbed and I tightened my grip on Carol's bottom, staring into her wickedly gleaming eyes.

"Just like your little Mary," chuckled Carol.  As we continued kissing I felt my sister's presence behind me.  She pressed up against my back, her silk-clad breasts and belly and hips touching me sensuously.  Then her lips, kissing me low down on the base of my neck.  Then biting lovingly...

"Ow!  Mary!"

Mary giggled and wrapped her arms around me from behind.  She slipped her hands between my body and Carol's, finding my cock with her fingers and encircling it tightly.  Almost immediately Carol pulled away from me.

"Not so fast, Mary.  I want to hear you beg for it."

Mary's lips paused on my neck.  "Beg for what?"

"Beg to fuck your brother..."

Mary was quiet for a moment, her lips pressed to my neck, her breath hot on my skin, her fingers lightly encircling my erection.  "Please, Carol?  Please let me fuck him?"

Carol chuckled.  "You can do better than that, Mary.  Convince me that you really, really want to fuck your brother."

"Oh Jesus, Carol, stop teasing me!  Please!  I need it so bad!  Please, Carol, I want to fuck him desperately!  I need to!"  Mary's voice was loud and husky in my ear.  It was incredibly erotic hearing her begging for me, to have sex with me.  "I'll do anything for you Carol, just please, PLEASE let me fuck Brian!"

"Describe it to me," Carol chuckled.  "Tell me how it would be."

Mary hesitated.  "I'd... I'd pull him onto the bed.  Please Carol, let me take him into our bed!  I... I want to feel his cock inside me.  It's been so long, Carol... so many years!"  Mary tightened her fingers on my cock, squeezing me gently.  "Please Carol, I want him to fuck me hard.  I want his cock in my cunt, his lips on mine.  I want him to pinch my nipples with his fingers, to hurt me just like you do.  Please Carol, I... I want to feel him cum inside me..."

Mary had never been shy about using dirty words before, but the way in which she used them now aroused me more than ever before.

"I'm still not convinced," Carol said.

"Carol, PLEASE!  For god's sake, please let me fuck him!  Oh god, Carol, please!?"  Mary sounded desperate now, even distraught.  Was she near tears?  It sounded like it, but I couldn't be sure.  Was her distress from the embarrassment of having to beg so explicitly, I wondered, or because she was so aroused?  I guessed that it was probably a little bit of both.

"Okay," chuckled Carol, "You've convinced me.  But what about you, Brian?  Do you want to fuck your sister as badly as she wants to fuck you?"

"Yes!" I exclaimed, pulling desperately on my bonds.  "Please Carol, let me fuck my sister!"

An amused smile flickered across Carol's face.  "Carol?"

"Ma'am!" I quickly corrected myself.  "I'm sorry, ma'am!"

"You will be sorry," Carol smiled.  "I was just about to let you fuck your sister, but now you're going to have earn it."

I groaned inwardly.  I couldn't take much more of this teasing!

With a wicked grin Carol pulled me away from my sister.  Mary reluctantly let me go with a final squeeze of my cock.  Carol led me to their bed and urged me onto it, coaxing me to lie back.  The silken sheets were cool and smooth against my naked skin, so soft and luxurious.  Carol took my hands in hers and pulled them out over my head, guiding me to grasp the posts at each corner of the bed.  Then she moved down and coaxed my legs apart, so my feet were at the posts at the other end of the bed.  I waited, spread-eagled and breathless, as Carol took Mary's hand and led her to the side of the bed.  She whispered in my sister's ear, and then – dear god – they began slowly, teasingly peeling their stockings down in unison.

I watched their little strip-tease breathlessly, my cock throbbing as one by one they slipped their stockings off.  Now Carol was completely naked, and my sister nearly naked wearing only her sexy silk basque.  Without a word they joined me on the bed, Mary between my legs facing away from me and Carol straddling my chest.  I could feel Carol's wet pussy lips against my chest, feel her silky smooth legs pressing against my sides.  With a smile she leaned forward, smothering me suddenly with her large breasts.  With a stab of excitement I twisted my head and found a nipple, sucking it eagerly as Carol giggled and rubbed her chest into my face.

I was barely aware of my sister's hands on my legs, then lower on my ankles.  Something touched me there, soft and silky, encircling my ankles.  First my left, and then my right.  I felt the same on my wrists as Carol followed suit.  My left leg pulled taught as Mary tied me off to the bed post.  Their stockings... they were tying me to the bed with their stockings!

I groaned into Carol's breasts as my right leg pulled taut, and then my arms.  I tugged gently at the stockings that bound me and found them secure.  Carol let me suck a moment longer on her breasts, and then she sat up.  But she made no move to get off me.

"Can you get free, Brian?"

I tested my stocking bonds and shook my head.

"Try harder," Carol said.  "I want you to really try..."  As she said it she reached out and tickled my armpits.  I jerked, pulling instinctively at my bonds.  Carol giggled and dragged her fingernails down my sides, tickling and scratching me.  With a grunt I twisted, trying to get away, but my bonds were too tight and with Carol sitting atop me I couldn't escape her tickling torture.  She reached back behind herself and dragged a fingernail up the underside of my swollen erection.  Then she squeezed my balls, hard.  I gasped and jerked at my bonds.

"I think they'll do," Carol observed with a smile, apparently satisfied that I couldn't get free.  She twisted atop me and reached for the nightstand.  When she turned around again she had two more black stockings.  "One for you..."  Carol tossed one of the stockings onto my chest, then turned around to face my sister who still knelt at my feet.  "...And one for you.  Hands behind your back, Mary."  My sister put her hands behind her back and Carol quickly bound them with the stocking.  God, Mary looked so incredibly sexy wearing nothing but the basque, her hands bound helplessly behind her back.

Carol turned back to me.  "We can't have you peeking for this next part," she teased me as she picked up the remaining stocking.  She placed it over my eyes, plunging me into blindness, and then wrapped it around my head and tied it off tightly in back.  "Can you see, Brian?"

I shook my head.  I couldn't see anything, not even a little bit.

"Good.  From now on you'll do your ‘seeing' with your cock."  I frowned, confused.  What did she mean?  "I'm going to suck your cock now, Brian.  Or will it be your sister?"  Carol's voice was teasing and as she spoke she lightly played her fingers over my chest.  "Your task is to tell who's sucking you.  If you guess correctly, I'll let you fuck your sister."

Oh God!  Just the thought of either one of their mouths on my cock was exquisitely arousing.  I lay helpless and blind as Carol and Mary shifted around on the bed.  I tried to follow their motions, to keep track of who was where, but to my dismay they got off the bed and moved around the room, defeating my best attempts to follow them by sound.  When they remounted the bed I had no idea who was where.

I waited helpless for the first touch.  When it came it wasn't lips or even fingers but hot, sweet breath, washing exquisitely over my stiff erection.  Fingers teased me gently, lifting my cock from my belly, and then a tongue flicked over the tip.  I groaned.  The tongue flicked again, and again, playing along the little slit in the tip of my cock.  Then lips, sweet, luscious lips, encircling my cockhead slowly.  I jerked at my bonds, instinctively trying to move my hands to whoever's head it was between my legs.  Whose mouth was it?  Carol's, or my sister's?  I couldn't tell for the life of me, even as the lips began sliding down my shaft, swallowing me inch by inch.  Then back up again, then down further.  I throbbed in the warm, wet mouth.  Whoever it was, she had no trouble deep throating me.  I soon felt her lips around the base of my cock, her nose on my belly, her tongue tickling the underside of my shaft.  Oh God, it felt so good!  It was Mary... definitely Mary.  I thought I could smell my sister's perfume, and the way in which she worked her mouth on my cock reminded me of how she had sucked Carol's strap-on earlier.  I was sure it was my sister but I didn't want the blow job to end, so I kept quiet for a while longer until I felt I couldn't hold out any longer.

"Mary!" I gasped.  "It's Mary!"

The mouth came off me slowly, teasingly.  It paused at the tip of my cock, sucking gently as my blindfold was removed.  I looked down and felt my heart sink.  It was Carol!

Carol was looking up at me sweetly, smiling around the tip of my cock.  She gave me a final, quick suck and then took her mouth off me.

"Sorry Brian," Carol teased.  "Would you like to try again?"

"Yes!  Please!"

The blindfold came down again, plunging me back into blindness.  Carol and Mary left the bed and moved around again before rejoining me on the silken sheets.  This time there was no pretense, no teasing.  Fingers lifted my cock and a mouth engulfed it, taking it deep but not nearly all the way.  This mouth was tighter, more eager.  It started bobbing on me enthusiastically, the teeth dragging lightly on my shaft.

"Mary... this time it's Mary," I said.  I could tell this mouth was different than the last.

The blindfold lifted.  Again I felt my heart sink.

"You're not doing too well," Carol teased me as she tickled my cockhead with the tip of her tongue.  "Want to try one more time?"

"Yes, please," I agreed, though less assuredly this time.  I had thought for sure this mouth had felt different.

Again blindness.  Mary and Carol moving around, on and off the bed.  A mouth came on my penis, sucking teasingly just on the tip.  I waited for it to engulf my shaft, but it didn't.  Instead it remained sucking on my cockhead, the tongue lapping down to tease the underside of my shaft.  Was it Carol, or was it my sister?  I couldn't tell, not for the life of me.  Teeth nipped at my sensitive glans and I jerked in my bonds.

"Carol," I gasped reluctantly.  "It's you, ma'am."  I knew she would think I would expect Mary's mouth on me now, after twice of hers, and no doubt she would try to trick me again.  The blindfold lifted.

"No!" I exclaimed in frustration.  My sister was looking up at me, her sweet, heavenly lips wrapped around the tip of my cock.

*    *    *

"I thought for sure you would guess right that time," Carol teased me.  I didn't say anything.  I was frustrated, and a bit distracted as Mary kept sucking on the tip of my cock.  "Since you can't tell my mouth from you sister's," Carol continued, "maybe you can tell our pussies apart?  What do you think Brian... would you like to try?"

"Yes, please!"

"Okay," chuckled Carol, "don't get too excited though... you'll spend yourself before you even get inside your sister!"  With a devious smile she pulled the blindfold down over my eyes again.  Mary's mouth left my cock, and they slid off the bed.

"Now, Brian, your sister and I are going to sit on you.  If you can guess who's on your face, I'll let you fuck your sweet sister."

I groaned at the thought.  Mary and Carol moved around in the bedroom, throwing me off, and then they rejoined me on the bed.  As one straddled my waist, the other straddled my face.  I opened my mouth eagerly in anticipation, excited by the prospect of having either one of these beautiful ladies sit on my face.  I didn't have to wait long.  The woman on my face sat down, her shaven pussy pressing to my mouth.

"Mmmm..."  I licked instinctively at the tight, wet slit, probing with my tongue.  The woman, whoever she was, was facing my feet.  I pushed my tongue into her tightness, delighting at how wet and receptive she was.  Carol?  Or my sister?  I tried desperately to place the taste, but then I found myself distracted by another sensation.  Fingers on my cock, lifting and positioning.  Then wet, exquisite tightness.  The woman straddling my waist was sitting down on my cock...

"Mmm!"  I groaned into the pussy on my mouth as the other enveloped my cock.  I humped upwards instinctively, burying myself in whoever it was.  Oh, sweet heaven!  She sat down on me completely, her weight pressing my cock even deeper into her pussy.  Then she began moving on me gently, rocking back and forth, grinding her crotch against mine.

I was in heaven.  One woman sitting on my face, the other sitting on my cock.  I licked eagerly, trying desperately to pleasure whoever it was on my face, at the same time grinding my hips upward and enjoying the tight sheath that enveloped my cock.  It clenched on me, milking my cock gently as we moved together.  I pulled in vain at my bonds.  I no longer cared who was where, I just wanted my hands to be free so I could touch them, love them, pull them closer.

I was enjoying myself so much that I almost forgot the purpose of this little tease.  Now I redoubled my efforts to identify who was where.  Earlier, when I'd sucked Carol's pussy through her panties, I had thought she tasted distinctly different than my sister.  But now I couldn't tell for sure who I was licking.  In fact, I thought I tasted both of them.  Was I imagining things, or was I perhaps confused in my blindness?  Maybe I was tasting both of them.  They had shared a strap-on dildo; maybe I was tasting their mixed juices.

"Carol... Carol's on my face," I finally guessed, my words muffled by the pussy that smothered me.  I dreaded the removal of my blindfold, and when it came I groaned with dismay.  From my helpless vantage point I had a clear view up the backside of the woman who sat on my face, and now I clearly saw my sister's hands still bound behind her back with the stockings, and her sexy silk basque.

"I guess you can't tell our pussies apart," Carol teased as she clenched her pussy on my cock.  "What a shame.  I was so looking forward to seeing you fuck your sister."

I groaned.  Her and I both!

I expected Carol and Mary to get off me now, but instead they remained on my face and cock.  Mary was rocking her pussy gently against my mouth, obviously enjoying my lips and tongue.  I licked her harder, pressing my nose into her pussy as I searched with my tongue for her clit.  I found it and she gasped.

As I pleasured my sister with my lips and tongue Carol began riding me in earnest, fucking herself on my cock.  I groaned into Mary's pussy.  Then I saw Carol's hands on the back of my sister's neck, pulling her forward.  They leaned together over me and a moment later I heard wet, sucking noises.  They were kissing above me as they straddled my face and cock.  I could hear them clearly and it excited me.  I was all but ignored now, nothing but an eager, helpless set of lips, tongue and cock available for their pleasure.  And I tried desperately to make it their pleasure, even if I couldn't be inside my sister.  I licked and nibbled and probed Mary's pussy eagerly, at the same time humping upwards with my hips to meet Carol's motions.  Her thighs tightened around my waist, and Mary's around my head, trapping me tightly with their sweet, silky smooth flesh.  I inhaled deeply, smelling my sister's musky, exotic aroma.  Then I felt a touch on my chin.  Fingers... Carol's fingers.  She was searching for Mary's clit, and when she found it my sister groaned and rocked harder against my mouth, moaning with delight.

Despite the exquisite sensations I felt like I was being punished.  Tied and helpless, unable to fuck my sister or even to pull her close as she ground her pussy on my mouth.  Oh, if I could just have one hand free!  But I was forgotten and ignored, my groans muffled in Mary's pussy.  I thought they would keep me there like that forever, until they had exhausted themselves and forced me to spend inside Carol's pussy, but finally they broke their kiss and pulled apart.

"Please Carol," my sister begged quietly, "won't you at least let me sit on him for a little bit?"

Carol seemed to think it over.  "Okay, since you two have been so good.  But just for a little bit, Mary.  And don't you dare make him cum with that sweet pussy of yours... he hasn't earned that yet."

"Oh, thank you Carol!"

Mary pulled her pussy away from my mouth and slid off me with a smile.  I wasn't sure whether to feel glad or disappointed.  The sudden prospect of having Mary on my cock was exquisite, but under orders not to cum!?

Carol didn't pull off my cock.  Not yet.  Instead she kept fucking herself on my cock, grinding her hips forward and back and leveraging my erection around inside of her.  The sensations were exquisite.  She felt so tight and hot and wet on my cock.  As she fucked me she put her hands on my chest and began toying with my nipples, pinching and teasing.  I sucked in my breath sharply and she smiled.  Then she leaned forward and draped her body atop mind, her large soft breasts pressing against my chest.  Her breath was hot on my face as she smiled down at me.

"What do you think, Brian?  Would you like to finish inside me, or do you want your sister to sit on you?"  I started to open my mouth, but Carol stopped me with a devious smile.  "Remember, if you choose your sister, you don't get to cum."

It was a terrible choice.  Either way would be exquisite... to cum inside Carol's luscious pussy, or to feel my sister's on my cock.  But did I want to fuck Mary enough to forgo my dreadfully needed orgasm?  Could I forgo it?

"My... my sister," I gasped.  I'd waited so long, dreamt about it so many times that there was no other choice.  I just had to fuck her, just once.

Carol smiled down at me, and for a moment I thought she was going to torment me further.  But instead she kissed me gently on the lips and then pulled off my cock.  I groaned as my erection slipped from her tightness and slapped back wetly against my belly.

"Okay Mary," Carol said sweetly.  "Have a seat."

I stared up at my sister with delight as she straddled me.  She smiled down at me, her cheeks flushed.  I could see the lust in her eyes, and the love.  I knew she felt for me what I felt for her.  She settled her pussy against my cock, trying to coax it into her tightness.  With her hands bound helplessly behind her back it was awkward.  Mary struggled for a moment but couldn't quite maneuver my cock into her pussy.

"Here, let me help you," chuckled Carol.  She reached out and guided my cock to my sister's pussy, nestling the tip between her shaven labia.  I didn't wait for Mary to sit down.  I couldn't wait.  I humped upwards, burying myself to the balls in my sister's pussy.

"Oh, Brian!"

I didn't say anything.  Mary's pussy felt so exquisite on my cock, so tight and hot and receptive.  Just like I remembered it.  She settled down on me with a groan, her weight pressing my hips back to the bed.  For a moment we remained still, joined at our sex.  Mary smiled down at me, and I up at her.  I wished desperately that my hands were free, that I could take her in my arms and make love to her properly, to fuck her like she'd begged for earlier.  As if reading my thoughts Mary began moving on me, teasing my cock with slow, gentle rotations of her hips that made my hardness lever around inside her pussy.  She leaned forward and kissed me, her silk basque so soft against my chest, her breasts and belly and legs so sensuous and erotic against mine.  She closed her eyes and began humping on me, but I kept mine open.  I wanted to see her face, see her expression as she rode me.

As Mary fucked me, Carol coaxed her to sit back up on my cock.  She took Mary's earlier place on my face, straddling me and lowering her own pussy onto my mouth before I could protest.  As much as I loved the thought of tasting Carol again, I even more wanted to keep kissing my sister.  But I was helpless to protest, and so I began licking Carol's pussy.  As I did Mary tightened her pussy on me, clenching me rhythmically as she rode me.  I was in bliss...

Carol's voice soon broke my concentration.  "Remember, Mary, you can fuck your brother as long as you want, but if he cums inside you I'm giving you a hundred strokes with the riding crop... hard.  You won't be able to sit for a week."

Mary gasped and I felt her pussy clench on me at the mention of the riding crop.  She was obviously appalled by the threat of such severe punishment, and so was I.  But there was no way I was going to be able to keep from coming.  Not for anything in the world.

Our fuck was over all too soon.  Mary rode me eagerly, rising and falling on my cock with delightful gasps.  But the threat of the riding crop was too much.  Just when I was getting close, Mary lifted herself reluctantly off my cock.

"No!" I groaned.

"What a pity," Carol chuckled as she ground her pussy into my face.  "It looks like your brother was close."

I grunted into Carol's pussy.  I had been close... so very close.  Carol enjoyed my lips and tongue for a moment longer, then pulled her pussy away from my face.  She turned around on me and slid down my body until we were face to face again, her breasts soft and luscious against my chest.  With a smile she reached between us and found my cock with her fingers, once more guiding it into her tightness.

"I'll tell you what, Brian," Carol said as she began riding me slowly.  "Just to show you that I'm not a complete bitch, I'll give you one last chance to fuck your sister.  If you can fuck me hard for ten minutes, I'll let you have Mary however you like.  Deal?"

I nodded, too beside myself to speak.  Carol smiled, then leaned over and unbound my sister's wrists.  "Okay Mary, untie your brother so he can fuck me properly..."

*    *    *

Mary untied me as I lay helpless beneath Carol.  She unbound my ankles first, then my wrists.  As soon as my hands were free I wrapped my arms around Carol and turned her, pinning her to the bed.  My cock slipped out in the process and Carol giggled.

"Brian!"

"Shut up," I hissed at Carol without thinking.  She laughed at my sudden words.  I didn't want her to speak.  I just wanted to fuck her, and for the ten minutes to be up so I could be with my sister properly.  I leaned forward and supported myself on my elbows on either side of Carol's head as I thrust back inside her.  As I began fucking her she wrapped her strong legs around my waist and gripped my sides.

"Harder, Brian!" Carol demanded.  She was smiling up at me with amusement, her beautiful eyes gleaming so wickedly.  "Fuck me harder, and don't you dare stop!"

I fucked Carol as hard as I dared, which was difficult to do without cumming inside her tightness.  Her pussy felt so good on my cock, so marvelously snug and wet as I pounded into it.  The sounds of our heavy breathing and of our sex filled the room.  Mary was forgotten for the moment, somewhere out of my sight.  I felt strangely guilty for fucking Carol in front of my sister, as if I was somehow cheating on Mary.  But before I could ponder that thought Carol dug her fingers into my sides, scraping me with her fingernails.

"HARDER, Brian!"

I grunted and captured Carol's lips with my own, biting her lower lip.  If she wanted hard, I would give her hard.  I pounded into her pussy, forcing her backward on the bed with each thrust.  She tightened her legs around me, pulling me into her deeper.  I bit her lip again, harder, and Carol laughed with delight.  She slipped her arms around me and raked her fingernails down my back, scratching me painfully from my neck down to my waist.  Then lower, clutching my bottom and pulling me into her as she tightened her pussy on my thrusting cock.

"You bitch!" I exclaimed without thinking.  She was trying to make me cum!  Carol laughed at my plight and began milking my cock with her pussy, teasing me closer and closer toward orgasm.  I had to slow down and pace myself, but when I did Carol dug her fingers harder into my bottom and urged me on with a wicked grin.

"Don't you dare slow down, Brian!  You owe me ten hard minutes."

I grunted with frustration and reached back and grabbed Carol's wrists.  I forced her hands out high above her head and pressed them into the bed, holding them there as I fucked her.  I half expected her to rebel, to struggle out of my grip, but instead she laughed up at me with delight in her eyes.

"That's it Brian, hold me down!  Take me!  Cum inside me... you know you want to!"

I did want to, desperately.  But I couldn't.  Not before I'd had a chance to fuck Mary properly.  I glanced at the clock and groaned.  Three more minutes to go.

Fucking Carol was exquisite torment, having to ride her so hard but not cum.  Three more minutes seemed an impossible eternity, but I just had to save myself for Mary.  I paced myself as best I could, but each time I slowed too much Carol urged me faster.  Her cheeks were flushed now, her breathing heavy.  She was as turned on as I was, and as I fucked her she wriggled a hand free of my grip and slipped it down between our bodies so she could finger her clit.

"Keep fucking me, Brian!" she hissed as she frigged herself.  "Don't stop!"

I didn't plan to.  I was going to finish the ten minutes, and then I was going to fuck my sister silly.  I'd been waiting too long not to.  As I thought about this I felt Carol's pussy tighten on me.  I looked into her eyes and saw that she was about to cum.  Her fingers worked frantically between our bodies, stroking her clit.  I could feel her fingers against my cock as I thrust inside her tightness.  I watched her intently, fascinated by how she looked as she approached the edge.  Her smile faded and became a grimace.  Her eyes drooped shut dreamily, then squeezed tight as she gasped.  I wondered what she was thinking about.  Me?  Mary?  Something else?  She grunted as she orgasmed, frigging herself frantically.  I could feel her pussy clenching on my cock in her orgasm.  Without thinking I pressed my lips to Carol's, kissing her passionately as she came.  She moaned into my mouth and tightened her legs around me.  I thrust into her hard and she bucked her hips upward, at the same time arching her back and pressing her breasts against me, riding me through the waves of her orgasm.

Afterward Carol's legs loosened around my waist and then fell limp at my sides.  With a contented sigh she relaxed beneath me.  I glanced at the clock and saw that the ten minutes were up.  I'd made it.

"Thank you, Brian," Carol told me softly, smiling up at me dreamily.  "I needed that!"

"It was my pleasure," I told her with a smile.  And now my next pleasure would be my sister.

As if reading my mind, Carol chuckled.  "Okay Brian, you've earned it.  Give your sister the fucking she deserves..."

*    *    *

My heart leapt.  I pulled slowly out of Carol's tightness, groaning as she squeezed me one last time.  I turned to Mary, eager and ready to mount her after waiting so long.  But before I could move onto her Mary pushed me back on the bed and straddled me instead.

"Mary, I--"

My sister silenced me with her lips, kissing me as she used one hand to guide me into her.  There was no threat of the crop now, no more teasing, no more torment.  She settled down onto my cock and began riding me eagerly, uninhibited for the first time all evening.  As she fucked me she kissed me again, and again, and again.  On my lips, my nose, my cheeks, my neck.  As she moved on me I slipped my hands between our bodies and felt for the laces on the front of her basque.  I wanted to feel her completely naked in my arms as we fucked.  As I unlaced her basque Mary sat up to give me better access, grinding her hips in little circles and teasing me with her pussy.  I gasped and slipped the basque off her, quickly pulling her into my arms and delighting in the feel of her naked breasts and belly and body against mine.  Her skin was so soft, so sensuous.  I had fantasized about this for so long, holding Mary in my arms again, naked and unfettered.  I hugged her tight and found her mouth with mine, kissing her deeply.

"I love you, Brian," Mary gasped into my mouth.  Her voice was husky and filled with lust.  I tried to answer back, to tell her that I loved her too, but her lips were on mine again too quickly, kissing and teasing and nibbling.  I gave up trying to say anything and wrapped my arms around her, pulling her close and savoring the feel of her naked body against mine as we moved together.  I felt like we were two young lovers experiencing sex for the first time.  In a way we were... we were experiencing each other for the first time, at least as mature, grown adults.  It was so much better now than ever before, no more hesitant youthful attempts, no more guilty abortions of our plans under threat of being suddenly discovered.  Now there was no one to stop us, no one to judge us.  I pulled my lips away from Mary's and buried my face in the base of her neck, biting her gently and humping up into her exquisite tightness.

We fucked like this for a long time, Mary on top, until I couldn't wait any longer.  I just had to fuck my sister properly... from the top, between her legs, fucking her like I'd dreamt about for so long.  I put my hands on her legs and coaxed her off me.  As my cock slipped from the tight clasp of her pussy Mary groaned in frustration.  But I wasn't going to let her be frustrated for long.  I quickly rolled her over and mounted her from above, moving between her legs and guiding my cock back to her sweet pussy.  She smiled up at me with flushed cheeks.  God she was so lovely.

As I moved onto Mary, and into her, I was vaguely aware of Carol slipping out of bed and leaving the room.  I silently thanked her, grateful for her consideration in letting Mary and I share this moment alone.  I smiled down at my sister and pressed up into her slowly, not wanting to rush such an exquisite moment.  As my cock sank deliciously into her pussy Mary wrapped her arms and legs around me and pulled me close.

"Mary, I--"

"Don't say anything, Brian," she told me softly, digging her heels into the back of my legs and clutching my neck tightly.  "Just fuck me... hard!  Like you did Carol!"

I felt a rush of excitement to hear Mary refer to how I had fucked her lover... and even more excitement that Mary would want me to fuck her like that.  I pressed my lips to hers and kissed her deeply as I began fucking her, pumping eagerly up into her tight pussy hard like I had Carol's.  Mary felt so deliciously warm and tight inside, her pussy so snug around my cock.  Her arms and legs felt so good around me, her lips so loving on mine.  Her eyes were wide and locked on mine as we rocked together, as if she didn't want to look away from me for a second.  I didn't want to look away from her either.  I kept my eyes on hers and kept kissing her as we fucked.

We were oblivious to the time.  We might have fucked for two minutes or twenty, I really don't know.  Before, with Carol, I had struggled not to cum.  I still needed to, desperately, but now with Mary I felt like I could hold off until we had both satisfied our pent up lust.  And it was lust.  There was no other word for it.  For the moment we were no longer brother and sister but two lovers entwined.  Mary clutched me tight and stroked my back lovingly, not scratching me like Carol had.  I liked both, but Mary's way was softer, more tender, more loving.  More how I felt for her.  I thrust up into her eagerly, fucking her hard like she had begged for, hoping she liked it as much as I did.

After a while I slowed my thrusting.  I wasn't done, not by a long shot, but something had caught my eye.  The stockings that Mary and Carol had used to tie me up earlier still lay discarded on the bed.  Now I reached for them, a thought forming in my mind.

"Oh Brian, please don't stop," Mary groaned.  She clutched me tighter and tried to get me to fuck her again.  But I only smiled and remained still between her legs.

"Hands over your head, sis..."  I held up one of the stockings suggestively and Mary's eyes widened.  She was flushed before, but now I saw her blush deeply with excitement.  Without a word she put her hands over her head, reaching out to grip the headboard.

I slipped my cock out of Mary's pussy – at which she groaned reluctantly – and moved up to straddle her chest.  Like I had done earlier, when we'd played briefly in the guest bedroom, I made her stretch her arms out to the corners of the bed and began to tie her wrists to the headboard with the stockings.

"Tighter, Brian... make it hurt, please?"

I pulled the stockings tighter around her wrists until she winced, and then I tied them off.

"Thank you," Mary gasped.

I wasn't done yet.  In our youth we'd been satisfied with binding each other's wrists, but now I thought something more was appropriate.  There was no sense in doing this halfway, and we still had several good stockings left.  I lifted Mary's left leg and pushed it up so her knee was nearly at her chest.  Then I looped one of the remaining stockings under her knee and around her arm and tied it off tightly.

"Brian!  What are you doing?"

I smiled down at Mary but didn't say anything.  I lifted her right leg and did the same, pushing her knee up to her chest and securing it there with a stocking under her knee and around her arm.  With her knees at her chest, helpless to lower her legs or protect herself with her arms, Mary looked exquisitely inviting.  Her pussy pouted open, wet and glistening from our fucking.  I could see her belly rise and fall gently with her breathing, see the flush in her chest and cheeks.  Unable to help myself, I reached out and gently teased my fingers down the helplessly exposed backsides of her legs.

"Brian, stop!" Mary giggled.  "That tickles!"  My sister squirmed and I did it again, tickling my way down the backs of her legs and then nearly to her pussy, smiling as I teased her.  She squirmed with the sensations, but not nearly as much as when I moved my hands to her sides and began tickling her there.

"Brian!  Please!"  Mary had always been ticklish.  We'd played with it a bit in our youth when I'd tied her wrists, but she'd never been nearly as helpless as now.  I took the opportunity to explore her body intimately, tickling and teasing her all over... her breasts, her arms, her belly, her legs. Even her pussy, touching and pinching her clit before teasing her pussy lips apart and slipping one, then two, then three fingers inside her tightness.  She felt exquisite, so wet and ready from our earlier fucking.  It made me eager to be inside her again.

I moved between Mary's legs and hesitated, my cock poised at her cunt.  "Maybe I should just jerk off and cum on your pussy," I teased her.

"No, please don't Brian," she moaned.  "Please, keep fucking me."

"You sure?"

"Yes!  Damn it Brian, just fuck me!  Please!"

My lovely sister, tied up and helpless, her pussy open for me, begging me to fuck her... I was in heaven!  I pressed forward and sank into her tight sheath.  Mary moaned loudly with approval.  I began fucking her, then hesitated again as one more idea came to mind.

"Brian, stop teasing me!" Mary gasped.  She struggled beneath me, pulling in vain at her bindings.

I reached for the nightstand, where the nipple clamps still lay from earlier.  Mary's eyes widened but she said nothing as I brought the clamps to her chest.  Her nipples stood out prominently, so large and inviting perched atop her modest breasts.  I teased each nipple for a moment with my fingers, then slowly, gently let the clamps ease shut.  First the left, then the right.  As each clamp tightened Mary hissed through her teeth and her pussy clenched on my cock.  It was intensely arousing to feel her reaction through our joining, and I immediately began fucking her again, hard.

"Oh Brian, I--"

I twisted the nipple clamps and Mary tensed beneath me, gasping desperately.  I teased her tortured nipples a moment longer as I fucked her, and then I lowered myself so I lay pressed against her.  As we moved together, our bodies' motions gently rocking the clamps on her nipples, I leaned down and kissed Mary passionately.  Connected at mouth and crotch, our eyes locked on each others and our bodies tight together, my sister and I began fucking eagerly.

We were both desperate now, our need too great to ignore or postpone.  I thrust up into Mary, free now to fuck her without inhibition.  I missed her warm embrace but even more I loved the new look in her eyes: a look of pent up, animalistic passion.  She was more excited now, more vocal.  She obviously loved being fucked while tied up and helpless.  I fucked her how she wanted, hard and fast, thrusting deep and delighting in how tightly her pussy clasped my cock, how it clenched and milked me in her excitement.  I knew I was going to cum soon.  I slowed my stroking but Mary immediately protested from beneath me.

"Don't stop, Brian!" she hissed.  "Fuck me harder!"

So I fucked her harder.  We were soon right there at the edge, both of us together.  I felt my orgasm swell inside me and I started to pull out, planning to cum on my sister's pussy like I had in our youth.

"Oh no!  Brian, please... oh please, cum inside me!"

My sister's words filled me with lust.  I thrust back inside her, grunting with delight even as she met my thrusts and groaned happily.

Mary came first, grimacing as her orgasm crested.  She pulled against her bonds and whimpered, riding the waves of her orgasm.  Her pussy tightened rhythmically on my cock and it was all I needed to push me over the edge.  With a grunt I came, flooding my sister's clenching, cumming pussy with my pent up lust.

*    *    *

Afterward I gently, tenderly untied my sister and removed the clamps from her nipples.  Mary and I lay cuddling in each other's arms, enjoying the warm post-coitus togetherness.  We didn't speak.  My cock softened and slipped from her tightness, but still I held her in my arms.  I was in no hurry for our moment together to be over.  Her body felt so warm and soft and voluptuous against mine.  So sensual.  So much more like a lover than my sister.  I hugged Mary tighter, not wanting the feeling to ever end.

"Thank you Brian," my sister whispered softly as I held her.  "Thank you... I love you so much..."

I smiled and kissed her gently.  "I love you too, Mary."

As my sister and I lay cuddling, Carol came quietly back into the bedroom and without a word slipped into bed behind me.  She didn't say anything, as if she recognized just how special a moment this was for Mary and I.  As I kissed Mary softly and held her in my arms, Carol pressed up against me from behind, her large soft breasts flattening against my backside.  I felt my cock stir to have my naked sister snuggled in my arms and her lover cuddling me from behind.  As Mary and I smiled knowingly at each other, Carol slipped her arms around me from behind and encircled my waist, at the same time kissing the base of my neck in back.  Mary matched her lover's movements, slipping her own arms around me just above Carol's and leaning down to kiss the base of my neck in front.  I closed my eyes and smiled dreamily.  Sandwiched between these two beautiful, sensuous women, their warm naked bodies pressed against mine and their fingers and lips on me, I slowly, blissfully fell asleep.  The last thought I had before I drifted asleep was of Mary and Carol, and that we still had the entire weekend ahead of us...