Mark looked at me strangely after he calmed down a little, still panting, but under control.

"You want Matthew, Holly?"

"Yeah. I want him."

"But Holly, you never said anything about this before."

"You never told me you had the hots for Erin, either, buddy."

"Yeah, true. I thought you'd get upset."

"I did, Mark. I got very upset. But not for long. I trust you enough to let this happen, under the circumstances, but I'm not staying here while you play stud to your sister in law. Not a hope."

"I thought this was about helping out with a baby."

"Bullshit!"

"Yeah, alright, I admit it. I'm curious. I never played any of those girlfriend sharing games you hear about with twins, and I want to know what does it for Matt."

"And..."

"And Erin is sexy as hell. Okay?"

"Okay. Tell ya something, Mark?"

"What?"

"I feel the same. I want to see if Matt is different to you, even though he looks the same. And I'd love to be able to share notes with Erin. So it's okay. You can have the hots for Erin, if I can have the hots for Matt."

"Holly?"

"Uh huh."

"I love you so much, baby."

"Yeah, I love you too. Listen, don't take this as permission to stray, either. It's just the four of us, understood?"

"Understood. So now what?"

"Well, we go and tell them. And then... well, we fuck them both."

"Not now."

"Tell now, fuck later."

"What's later, Hols?"

"Might as well be tonight. You'd be no use now. I bet I get shit for letting you use up that baby juice too."

"Don't tell."

"Have you seen your face, husband mine? It's fairly obvious. So, tonight, yes?"

"Okay. What about logistics?"

"Oh, I don't care. Tell you what, how about I refuse to give up my bed. You go there, Matt comes here. That work?"

"Yeah, that works. Did I tell you...?"

"Yeah, you love me. I know. Let's go. Oh, wipe that first, for God's sake."

Dinner was a little hushed that evening. The four of us sitting there, quietly eating fish, and drinking beer and wine, as the preference took us. None of us were naked. Somehow it wasn't the same any more, at least not yet, and we needed clothes for protection. I did, anyway, and everyone else seemed to follow suit.

Matt and Erin had taken the decision well, with Erin dragging me into a bear hug while the boys did something similar. Then we swapped, and I was enveloped in Matt's arms while Mark and Erin got close. It was strangely innocent still, at that point, all of us coming to terms with what was happening. Erin seemed neither surprised nor upset with the idea of sharing Matt, and I wondered, yet again, if I was falling into a plan that she already had in place. I like Erin, but she has a devious streak, to say the least.

Matthew was gracious enough to admit that he had heard us earlier, from the deck, but wasn't sure if we were loving or fighting. He was pleased it was the former.

I discussed the rules as I saw them with the full team, and we agreed on guidelines. After that, we put the whole thing aside for a few hours, and went swimming, off the side of the boat, in the warm water, splashing and leaping around like children, before lying on the hot deck again, and telling stories. First sex experiences, would you believe.

Eventually, the hot sun became too much for my pale skin, and I fled to the galley, and fixed everyone a cold drink. As I started back outside, everyone came in, and we sat on the couches, drinking happily, and continued the stories, laughing at things we, or at least I, would never have thought of discussing before today, except with Mark. I really enjoyed it.

The funniest story related to Matthew getting caught jerking off. He was in the bathroom, back when he and Mark were still at high school, and it was their aunt that caught him. Realising the predicament he was in, and wanting to minimise the repercussions, he pretended to be Mark, and their aunt fell for it. In the end, it didn't much matter, because the Aunt was a little more trustworthy than they thought, and never said any more about it to anyone else. Even funnier than the story, was the fact that Matt had never told Mark about it until now. Everyone but Mark was literally rolling on the floor in hysterics, and Mark was sitting there slowly working out what some of the strange things his Aunt had said to him had meant. He vowed, in the finish, to dob Matt in at the first opportunity, but he didn't mean it. Eventually, he gave in and laughed with the rest of us, and Matt apologised.

As the afternoon wore on, I decided I needed a nap, and strolled back to our cabin, and collapsed on the bed. Nothing more happened, from my perspective, until Erin came in to get me for dinner.

She sat on the side of the bed, and gently stroked my shoulder to wake me up. That's just the nicest thing. As I started taking some notice, she stopped the stroking, and smiled at me instead.

"Hi Holly." She said quietly to me. "It's time to eat, hon. Are you awake?"

"Yeah, I am, thanks Erin."

"Listen, just before I go, I wanted to check with you. You want to go through with this?"

"Yeah, I said so already."

"Yeah, I know you did, but when you disappeared, I wondered if you were having second thoughts, and I didn't want this to come between us. Just say no, and it's all off."

"No Erin, really. I'm alright with it. More than."

"More?"

"I never thought I'd be saying this to you, but I want to fuck your husband. I want to feel him inside me. I want to come in his arms. Okay?"

"I feel just the same, Holly. They are some sexy men we have."

"I thought this was for a baby, for you?"

"Oh, it is. That part is all true. It's just that on a lower level, I want to do this anyway. That part is pure sex."

"Good."

"Yeah?"

"Yeah. It was going to be strange if we were doing it for the sex, and you were doing it for the baby. Multitasking is good."

"Yeah, it is Holly. God, I'm glad he married you, and not some of those other ones he went out with."

"Hee hee. Well, you heard his stories this afternoon. Some of them wouldn't want him back!"

"Yeah, well Matt didn't fare much better, you know."

"Yeah, I heard, Erin. Okay, you convinced I know what I'm doing?"

"Yeah, I am now."

"Good. Now get out. I'm going to dress for dinner."

"Oh, really? That's a good idea, Hol. I will too."

"Get out."

"Gone."

Erin took charge after dinner, as I knew she would, and moved some things around on the deck, clearing a space. I guessed what she was doing when she showed up with a CD player, and more wine.

She had chosen some good music, and we danced, drank, and laughed to a selection of oldies from when we had been at school, before she put on some slow romantic songs. Then the mood changed subtly, and I took Matt into my arms, and swirled him lazily around the deck. Erin was doing the same with my husband, and at some point, twirling past the open hatch, they disappeared, presumably to Erin and Matt's cabin. I had thought that I'd be little perturbed at this point, but I was just a little drunk, and dancing with a handsome replica of Mark, and I wasn't put out at all. Horny is what I was, in fact.

Not wanting to head downstairs just yet, I stood with Matt, swaying to the music, and pulling him closer to me. He tipped his head down slightly, and my lips latched on to his. I'd kissed him before, but it wasn't like this. His lips were probably identical to Mark's, but his technique was completely different, and I was immediately entranced. As my slightly open mouth touched his, our tongues sought each other out, writhing delicately in the shared space, exploring, stroking, preparing each other. The feeling was entirely bizarre, so familiar and yet so different, and I would have stayed there for hours, just kissing, but I wanted other things from the evening.

Without releasing our mouths, or saying a word, I reached down and caught hold of the bottom of Matt's shirt, slid it up his torso, and tried to pull it over his head. He had to let me go then, for a moment, and he took advantage of the fact to return the favour, has hands sliding over my bra, and creating a tingle as he passed my nipples, the fabric of my shirt in his hands, and being slowly pulled over my head.

As soon as these items were out of the way, we locked back together, mouth to mouth, and our hands explored each other's upper bodies, Matt removing my bra without a pause, his hands gently caressing my naked breasts, his fingertips sliding over my stomach, my navel, a gentle count of my ribs. My hands had found the muscles I had seen before, and I rubbed him all over, my thumbs causing him to shiver as I teased his little nipples. It seemed a fair exchange overall.

Matt's hands found their way slowly down to my shorts, efficiently opened the button, and slid the metal zip slowly down, and as he did that, my shorts began to fall of their own accord, and he let them go before grasping my panties at the sides, and sliding, rather than tugging them downward. I shivered again as the waistband slid over my mound, and wiggled my butt to make them fall to the deck with the shorts. I lifted my feet from them, and kicked them away, before turning my attention to Matt's shorts.

His hands had settled fairly firmly on my buttocks now, and I could only grab the top of his shorts, and tug downward. He wasn't wearing anything under them, and as I pushed them down, his penis burst from the front, rising happily in front of my belly button. Very little effort was required to lose the shorts at this point, so I concentrated on teasing his cock with my navel, wriggling around, my warm skin against the hot tip of it, Matt's grunts of satisfaction spurring me on.

The silence was broken then, as Matt spoke very quietly. "Holly, you have any specific plan here?"

"No Matt," I replied. "Just fuck me please. I'm hot as hell, and my husband is busy."

"My wife too. God, I thought I'd be jealous, but I'm just more horny."

"I know exactly how you feel. Now, Matt."

"Now?"

"Uh huh. No need for prelims."

Without another word, he tightened his grasp on my butt, pulled me tight to him, his cock between us, and then lifted me off the deck, pulling my legs up. As soon as I realised what he was doing, I did my best to assist, lifting and wrapping my legs around his waist, pulling myself up with my arms linked behind his shoulders.

As he steadied himself carefully then, he relaxed a little. He lowered me over himself, and slowly let me sink, his hardness creeping slipperily up inside me, filling me with both bulk and heat, and settled me in place before kissing my forehead. He really did feel very similar to his brother, though Mark would not have been able to hold me up like this, I don't think. Just as I was getting used to the feeling of him inside me, he started to move, lifting me gently off him, just a little, and letting me settle back, my nipples sliding delightfully up and down his chest, his nipples getting brief attention from my tongue where possible.

Once the motion started, it didn't change much. There was no need to speed up, and so long as he could hold me, I was more than happy to be impaled. I was so hot and wet that I could feel moisture dripping from me every time he pulled out a little. As the rhythm began to affect me exactly the way it was intended, I started to try to help, pulling again on his shoulders to left myself each time, pushing down a little on the return trip, my mind not on the tasks, but the feeling. The pressure and the heat were all encompassing, and I just enjoyed the ride.

It didn't take long for us both to become seriously aroused, though I wasn't quite sure if his panting was a result of arousal or the serious effort required to fuck this way. I could feel the tensions of the afternoon, the harmless laughter, and the deliberate romance of the evening flowing from me, replaced by a desperation for release, a need to come, to have him orgasm inside me, and I altered the angle between us every so slightly, working on each thrust to finish in the nicest possible way. In the end, the tension was too much, and as Matthew lowered me over himself one last, slow, deliberate, delightful time, he pushed me over the edge, and I clung to him desperately, my body wracked with spasms, my cunt glowing with pleasure, with release.

My gyrations were more than he could stand, and just as I started to calm down, he exploded inside me, his cock jerking deep within my hot loins, his panting mixed with groans, his hands almost dropping me as he thudded through an intense orgasm. I was stunned then that his release managed to push me again beyond reason, and I came for a second time, holding desperately to him now, basically hanging by hands and cunt as I shuddered indelicately against him, gasping for breath.

Matt managed to hold on to me for a while, and then slowly lowered me to the deck, his still thick but no longer hard cock slipping from my grasp. Our sweaty bodies clung to each other still, and we swayed silently again for a while, his fluids dripping unnoticed from me, my head tucked against his chest.

Eventually, we realised we were both getting cold, and we picked up our clothes, and anything the might blow away overnight, and padded down the hatch, heading for my cabin, whispering gently to each other, still stunned by the experience. We had to pass the cabin with Mark and Erin in it to get to there, and we noticed they had left the door open, so we shamelessly peeked. Erin was crouched over Mark's face, her hands flat against the wall, her hips thrusting against his tongue, groaning. Mark's erection was obvious, and I was pleased to think that Erin would take care of it for him.

Matt lowered his lips to my ear, pointing at the couple on his bed, and spoke very quietly. "There's an idea, don't you think?"

"Mmm, I agree. You want to lick me like that?"

"Not JUST like that, Holly."

"No, but first off."

"Yep."

"Now, Matt?"

"The other cabin, you slut."

"Oh. Alright."

"Come on then."

We sneaked back out of the cabin, and down to the other one, and leaped into the bed. Matt was half-erect again, so watching his wife and my husband had obviously affected him the same way as it had me.

I made him lie back on the bed, the same way Mark had been, but instead of presenting myself to his eager lips, I shimmied down the bed, and settled my face between his legs. The aroma of his fluids and mine was overpowering, and I felt compelled to lick it all off, knowing I'd have a chance to reapply it eventually. Matt relaxed to my ministrations, laying back quietly and letting me work on him.

After a fairly short time, his erection was back in force, and my lips slid up and down his shaft, my tongue applying variation to the movements, wriggling over the tip of it, feeling the pulses as I tickled and teased him. Eventually, I could feel he was almost ready again, and I played a mean trick. I stopped. I didn't let him go, but I slid off his penis, and licked my way up his stomach, then his chest, stopping when I was almost at his throat, to tease him a little more, by dragging my vagina up across the tip of his cock, and sliding gently back and forth a few times. I teased myself as well by not letting him inside me, just back and forth on my slippery labia.

I couldn't keep this up very long though, because I knew I couldn't resist sinking over him if I did, so I crept further up, letting his cock spring up between my legs, as my tongue found its way up to his chin, his face. Our lips locked together, and our tongues played a slower version of the game they learnt outside, entwining wetly together as we struggled to breath around them, his hands simultaneously exploring everywhere they could reach, even finding the little spot at the base of my back. He knew it too, because my mouth quivered, and transferred the knowledge to his. He did it again to check, before abandoning that too, until later.

I released his mouth then, reluctantly, and kept moving up his body slowly, allowing him to lick me now, first my wonderfully sensitive throat, then my breasts. I stayed there for quite some time, trying to work out what was different from the way that Mark did the same thing, and unable to quite work it out. I knew it was different, but I couldn't have said how.

Eventually, that also became too much, and I slid up further, allowing him to briefly explore my navel, and then I sat up, and settled myself down in the same position we had seen Erin in, his mouth directly below me, my dripping wetness begging for more. He didn't disappoint, pulling me tightly to him, clamping my thighs on the sides of his face.

He started slowly, exploring my labia gently, deliberately keeping away from my clitoris for a while, paying me back for the teasing, until I was willing him to touch me there, to remove his tongue from where his cock had recently been, and to pay me some direct attention. He ignored me for a while longer, and then took pity on me, his tongue sliding up effortlessly to encompass my clit, and he began to circle it, his tongue playing games with my most sensitive part, while his hands danced on my buttocks, somehow squeezing more arousal out of me than I had felt for a long time, tensing me somehow, on the edge or orgasm, but never quite there.

Finally, when I was begging out loud, he took pity on me, and at the same time as he took my clitoris into his mouth, and sucked gently on it, his hands found that spot again, on my back, and I couldn't take it any more. My legs clamped hard on the sides of his head, my nipples, squeezed by my own hands, became harder, and deliciously sensitive, and as I let them go, I let myself go, groaning as I came over his continually gyrating tongue. I jumped up from him then, suddenly needing something inside myself, and slid back down the bed, impaling myself on his cock again, hard. Matt had had all he could take as well, and a few thrusts from beneath me saw him coming again, his hot come spraying deep inside me, and I collapsed, shaking, on top of him, breathing spasmodically, and feeling his heart pounding beneath my head.

We lay there, still saying nothing, sighing together, learning each other's breathing, and, contrary to my normal after-sex habits, I fell asleep. Matt must have too, because the next thing I knew, I woke, curled in beside him, the sun shining, and my lover sound asleep beside me.

I could have felt some guilt then. I could have, but I didn't.