I know a guy isn't supposed to think about his sister as a woman, much less fuck her, but how many guys arrive home to find their sisters on all fours, blowing one guy while another fucks her from behind?

Emily is a year younger than me then, just fifteen, and she has, frankly, a fantastic, fucking body. I mean she has big, high breasts, long prefect legs, and an arse that every guy in our school had longed for.

When I came in early from work last week I came in the back door and got a beer from the fridge. I had just upended it when I heard her voice crying out from the living room.

"Oh fuck! Harder!" her voice cried. "Yes! Yes!"

I frowned and moved to the hall, then looked around the corner into the living room. There was Emily, her long hair wrapped around the fist of a very large, muscular naked guy at least ten years older than her. Her lips were wrapped around the guy's cock as she bobbed them up and down.

Her breasts were swinging back and forth below her as she knelt there, and another big muscular guy was giving it to her from behind, his hips smacking into her arse cheeks as he rode her. I watched in stunned amazement as he slid one of his hands up her body, then cupped one of her breasts, squeezing it tightly.

Okay, she was my sister, but my cock sprang up in an instant as I eased back and watched.

"Yeah. Suck it, baby," one of the guys growled.

"Tight pussy," the one behind her gasped.

Then he gave a hard flurry of strokes and halted, hands on my sister's back as he gasped for breath.

Emily pulled her lips off the other guy's cock and whirled around, spreading her legs as he moved in and thrust home.

He fucked so hard he was actually driving her across the floor, his hips slamming into her upturned arse cheeks and jerking her forward on her hands with every stroke.

Emily jerked her head up and back and her eyes closed as she took it, then she started tossing her head up and down, and her mouth opened as she gulped in air. Then she started crying out in pleasure, sharp little yaps at first, then long curses of pleasure as she came, her voice rising into a scream as the guy pounded his meat into her furiously.

She fell forward onto her elbows, then her shoulders as the climax passed, and the guy, having come as well, eased back onto his heels. I went back outside and waited for a few minutes for the guys to leave, feeling too fucking horny for my slutty sister to be mad at them for riding her like they had.

I went in the front door just as Emily pulled a short dressing gown around herself. She whirled and looked at me in a kind of guilty way as she tied the belt around her narrow waist.

"What's wrong with you?" I asked.

"N-nothing's wrong? Why?"

"You're in your dressing gown this late in the day?"

"I was...changing."

I looked her up and down, noting her flushed skin and the sheen of sweat on her forehead, then laughed.

"What's so funny?" she demanded.

"You've got some come on your cheek," I said with a smirk.

Her jaw dropped and she reached up automatically, then glared at me.

"Just changing, huh? I saw those two guys leaving."

"What guys?"

"Okay, I'm wrong. You know how you've been wanting my room? If you open that robe and are wearing anything beneath I'll give it to you."

"Just because I don't have anything under here doesn't mean..."

"Okay, if your pussy doesn't have jism in it you can have my room."

She glowered at me, then sighed and rolled her eyes. "Are you going to tell mom and dad?"

"Hell no."

She looked down and saw the bulge in my pants, then kind of smirked. "The thought of me getting boned turn you on big brother?"

"Not nearly as much as the sight of you sucking one guy while the other fucked you a couple of minutes ago."

She blushed and her mouth opened.

"Yeah, I came in the back way.

"I hope you got an eyeful!" she flared.

"Sorry," I said. "But you ought to put a sign on the door or something `I'm fucking, don't come in'."

Her face was beet red and I took pity on her.

"You looked gorgeous," I said. "Incredibly hot and sexy."

"Really?" She looked down at my crotch again, then up at me.

"Oh yeah. I wanted to jump in and join them."

She grinned, then reached forward and cupped my cock through my jeans. It grew under her hand and she smiled up at me teasingly. "Well nobody's stopping you now, big brother."

She undid her robe and shrugged it off, letting me drink in the sight of her hot, sexy body as she rubbed at my cock. She undid my jeans as I reached up and squeezed her breasts, then pushed them down and pulled my cock free.

She dropped to her knees in front of me right then and there, licking at my cockhead, then taking it into her mouth. I couldn't do a fucking thing but stand there and groan and run my fingers through her hair as her lips bobbed up and down on my burning tool.

She pulled back and looked up at me. "There's one thing I wanted that those guys didn't do," she said, pumping her hand on my now slick cock. "I wanted them to fuck me in the arse, but they just wanted my pussy."

I stared down at her in shock as she let go of my cock then turned and dropped onto all fours. She lowered her upper body to her shoulders, then reached back with both hands and gripped her buttocks, pulling them wide.

"You can fuck me as long as its in the arse, Mark," she panted.

Well, Christ, I sure wasn't going to turn that down. I was on my knees behind her in an instant and rubbing my saliva soaked prick against that little wrinkled hole.

I screwed myself in slowly, pushing my way through her tight rectum as my hands raced over her body. I sank my fingers deep into her titty meat, grinding and squeezing and mauling it in delight as she groaned and concentrated on keeping her sphincter from clamping down.

Then my hips were flush with her soft arse skin and she pushed herself up onto all fours, rubbing her arse back against me and groaning in delight.

"God it feels good back there!" she moaned. "I never had a cock up the arse before!"

"You got a gorgeous arse," I whispered, squeezing her breasts as I started to pump.

She started humping against me in tandem, and I quickly learned that Emily wasn't a girl for soft gentle lovemaking. She wanted it hard, fast and nasty, and cursed me until I started accommodating her.

Soon my hips were slamming into a pair of soft arse cheeks that were still red from the slapping the other two guys had given them, and my prick was slicing back and forth through my sister's arsehole as I pounded my meat inside her.

"Fuck my arse! Fuck my arse!" she gasped with every breath, saying it like a mantra as she slammed her butt back to meet each thrust.

Then she stopped talking entirely, just grunting like an animal as I rode her. I grabbed her hair like one of the other guys had done, yanking it back, holding it in both hands like the reins of a spirited filly as my cock skewered her hot, steaming little arsehole.

She started cursing and moaning and then screaming in pleasure as she came, her head back, her arsehole sucking like a mouth on my prick as I continued to hammer it home. That was too much for me and I exploded inside her, whitewashing her bowels with my sperm as she drank it all down.

We've fucked twice since then, once in the pussy and the second time up the arse again, and although it is a bit strange fucking my sister I can't say I'm not enjoying myself.

I know a guy isn't supposed to think about his sister as a woman, much less fuck her, but how many guys arrive home to find their sisters on all fours, blowing one guy while another fucks her from behind?

Emily is a year younger than me then, just fifteen, and she has, frankly, a fantastic, fucking body. I mean she has big, high breasts, long prefect legs, and an arse that every guy in our school had longed for.

When I came in early from work last week I came in the back door and got a beer from the fridge. I had just upended it when I heard her voice crying out from the living room.

"Oh fuck! Harder!" her voice cried. "Yes! Yes!"

I frowned and moved to the hall, then looked around the corner into the living room. There was Emily, her long hair wrapped around the fist of a very large, muscular naked guy at least ten years older than her. Her lips were wrapped around the guy's cock as she bobbed them up and down.

Her breasts were swinging back and forth below her as she knelt there, and another big muscular guy was giving it to her from behind, his hips smacking into her arse cheeks as he rode her. I watched in stunned amazement as he slid one of his hands up her body, then cupped one of her breasts, squeezing it tightly.

Okay, she was my sister, but my cock sprang up in an instant as I eased back and watched.

"Yeah. Suck it, baby," one of the guys growled.

"Tight pussy," the one behind her gasped.

Then he gave a hard flurry of strokes and halted, hands on my sister's back as he gasped for breath.

Emily pulled her lips off the other guy's cock and whirled around, spreading her legs as he moved in and thrust home.

He fucked so hard he was actually driving her across the floor, his hips slamming into her upturned arse cheeks and jerking her forward on her hands with every stroke.

Emily jerked her head up and back and her eyes closed as she took it, then she started tossing her head up and down, and her mouth opened as she gulped in air. Then she started crying out in pleasure, sharp little yaps at first, then long curses of pleasure as she came, her voice rising into a scream as the guy pounded his meat into her furiously.

She fell forward onto her elbows, then her shoulders as the climax passed, and the guy, having come as well, eased back onto his heels. I went back outside and waited for a few minutes for the guys to leave, feeling too fucking horny for my slutty sister to be mad at them for riding her like they had.

I went in the front door just as Emily pulled a short dressing gown around herself. She whirled and looked at me in a kind of guilty way as she tied the belt around her narrow waist.

"What's wrong with you?" I asked.

"N-nothing's wrong? Why?"

"You're in your dressing gown this late in the day?"

"I was...changing."

I looked her up and down, noting her flushed skin and the sheen of sweat on her forehead, then laughed.

"What's so funny?" she demanded.

"You've got some come on your cheek," I said with a smirk.

Her jaw dropped and she reached up automatically, then glared at me.

"Just changing, huh? I saw those two guys leaving."

"What guys?"

"Okay, I'm wrong. You know how you've been wanting my room? If you open that robe and are wearing anything beneath I'll give it to you."

"Just because I don't have anything under here doesn't mean..."

"Okay, if your pussy doesn't have jism in it you can have my room."

She glowered at me, then sighed and rolled her eyes. "Are you going to tell mom and dad?"

"Hell no."

She looked down and saw the bulge in my pants, then kind of smirked. "The thought of me getting boned turn you on big brother?"

"Not nearly as much as the sight of you sucking one guy while the other fucked you a couple of minutes ago."

She blushed and her mouth opened.

"Yeah, I came in the back way.

"I hope you got an eyeful!" she flared.

"Sorry," I said. "But you ought to put a sign on the door or something `I'm fucking, don't come in'."

Her face was beet red and I took pity on her.

"You looked gorgeous," I said. "Incredibly hot and sexy."

"Really?" She looked down at my crotch again, then up at me.

"Oh yeah. I wanted to jump in and join them."

She grinned, then reached forward and cupped my cock through my jeans. It grew under her hand and she smiled up at me teasingly. "Well nobody's stopping you now, big brother."

She undid her robe and shrugged it off, letting me drink in the sight of her hot, sexy body as she rubbed at my cock. She undid my jeans as I reached up and squeezed her breasts, then pushed them down and pulled my cock free.

She dropped to her knees in front of me right then and there, licking at my cockhead, then taking it into her mouth. I couldn't do a fucking thing but stand there and groan and run my fingers through her hair as her lips bobbed up and down on my burning tool.

She pulled back and looked up at me. "There's one thing I wanted that those guys didn't do," she said, pumping her hand on my now slick cock. "I wanted them to fuck me in the arse, but they just wanted my pussy."

I stared down at her in shock as she let go of my cock then turned and dropped onto all fours. She lowered her upper body to her shoulders, then reached back with both hands and gripped her buttocks, pulling them wide.

"You can fuck me as long as its in the arse, Mark," she panted.

Well, Christ, I sure wasn't going to turn that down. I was on my knees behind her in an instant and rubbing my saliva soaked prick against that little wrinkled hole.

I screwed myself in slowly, pushing my way through her tight rectum as my hands raced over her body. I sank my fingers deep into her titty meat, grinding and squeezing and mauling it in delight as she groaned and concentrated on keeping her sphincter from clamping down.

Then my hips were flush with her soft arse skin and she pushed herself up onto all fours, rubbing her arse back against me and groaning in delight.

"God it feels good back there!" she moaned. "I never had a cock up the arse before!"

"You got a gorgeous arse," I whispered, squeezing her breasts as I started to pump.

She started humping against me in tandem, and I quickly learned that Emily wasn't a girl for soft gentle lovemaking. She wanted it hard, fast and nasty, and cursed me until I started accommodating her.

Soon my hips were slamming into a pair of soft arse cheeks that were still red from the slapping the other two guys had given them, and my prick was slicing back and forth through my sister's arsehole as I pounded my meat inside her.

"Fuck my arse! Fuck my arse!" she gasped with every breath, saying it like a mantra as she slammed her butt back to meet each thrust.

Then she stopped talking entirely, just grunting like an animal as I rode her. I grabbed her hair like one of the other guys had done, yanking it back, holding it in both hands like the reins of a spirited filly as my cock skewered her hot, steaming little arsehole.

She started cursing and moaning and then screaming in pleasure as she came, her head back, her arsehole sucking like a mouth on my prick as I continued to hammer it home. That was too much for me and I exploded inside her, whitewashing her bowels with my sperm as she drank it all down.

We've fucked twice since then, once in the pussy and the second time up the arse again, and although it is a bit strange fucking my sister I can't say I'm not enjoying myself.