Not in any way you’d have imagined, your sister joins in and shares some dirty secrets of her own!

You look down at Mary, watching her hazel eyes intently, almost as if you can peer through them and watch the inner workings of her mind at work. You smile and grind yourself forwards, the precum slick tip of your erections brushing against Mary's black silky dress. You can feel the heat from Mary's pussy through the thin and fabric, being ruined at both ends in a mixture of her juices and your precum. You marvel at the sight of Mary squirming beneath you, biting her bottom lip so hard her teeth leave a light indentation as you grind your cock in a circular motion.

You ignore the sensation urging you to simply hike up Mary's dress and ravage her here and now; you want this to last a little while; you want Mary to beg for you to take her before you do. Instead, you reach forward and cup her large boobs in each hand, teasing the wonderfully soft orbs, while Mary lets out a series of soft moans. Within seconds you feel Mary's nipples pressing against the palms of your hands, the swollen nubs making themselves known through the soft fabric of her black dress and your light caress.

You manage to tease Mary a good ten minutes longer before she finally breaks and pleads for you to fuck her. Succumbing to the erotic pressure of feeling your length pressing into her body while your hands deftly stroke and caress her legs while you lightly suck and nibble at Mary's nipples through her dress.

"Please, Claire," Mary pants, while squirming as one hand slides beneath Mary's dress and teases her upper thigh; her soft skin gains a warm slickness the higher your hand climbs closer to her sex. "Please, I need more," Mary groans.

"What do you need?" You ask in a coy tone.

"I need you to fuck me," Mary groans.

"I thought we were just playing," You reply in a teasing tone. "Just enough to make Leslie jealous," You add, slowly sliding your hand back down Mary's thigh.

"I've changed my mind," Mary pleads, her words melting into a hiss of pleasure as you slide both hands along her legs until your thumbs come into contact with a thoroughly soaked pair of panties.

"What about my Sister?" You ask in a soft tone.

"She had her fun; now I need mine," Mary groans as you gently work your thumbs against her slippery mound.

"If you insist," You reply in a sultry tone.

You slide yourself back, stopping only to give Mary's Nipples on final nibble each before you continue and find yourself between Mary's long legs. Mary pulls her silky dress, now thoroughly stained with a mix of your precum and her delicious juices, over her head while you distract her by gently stroking her legs. You enjoy teasing Mary, watching her struggling to get her dress over her head for a few moments before something else catches your attention. Leslie, your half-sister, is standing naked in the open doorway. Your eyes meet hers, and just as your mouth moves in an attempt to say something, Leslie holds up a single finger to her lips and then nods her head towards Mary and gestures for you to continue with her bride to be.

You nod to your Sister and turn back to face Mary, who was almost free of her dress and smile as you attempt to adjust to this new development and try to think about how this might work in your favour. "Mmmm rollover, If we're going to do this, I really want to make that sweet ass jiggle," You purr. You didn't want to risk Mary noticing Leslie and risking her getting cold feet about getting fucked.

Mary eagerly complies, rolling onto her stomach and finally pulling her dress free; you reach down and take a grip of Mary's hips, guiding her up into an all-fours position. You position yourself right up against Mary's rear, teasing the tip of your swollen length against Mary's hot wet folds a few times.

"Wait, we need a condom or something," Mary pants.

"Awww, do we really?" You ask, teasing yourself against Mary's molten sex.

"Yes, I'm not on any kind of protection," Mary pants, "I have some in the bedside table," She quickly adds.

You quickly glance back to your Sister, who shakes her head while slowly walking silently towards you both. "Did Leslie use them when she had her fun?" You ask in a teasing tone.

"No," Mary groans as you press yourself forwards, the tip of your cock kissing the inner folds of Mary's juicy pussy before sliding away before slipping inside.

"Then I don't think we should either," You reply in a teasing tone. "You can trust me to pull out," You offer in a teasing tone.

"Fuck, it's too risky," Mary pleads, her **** melting away rapidly.

"It is, but doesn't that make it even hotter?" You continue in a teasing tone.

"Oh fuck, fine, take me raw then, just please don't cum in me," Mary pleads. "I don't think Leslie would forgive me if you knock me up," Mary pants burying her face into the bed.

"That's funny because I need you to knock her up for the same reason she says you can't," Leslie whispers softly into your ear. "After all, you pack quite a potent punch there, Sis," Leslie whispers before reaching between your legs and gently caressing your heavy balls.

Knowing Mary would need distracting before you could conduct any sort of conversation with your Sister, you press yourself forwards, the sweet slick lips of Mary's pussy parting eagerly to devour your cock. You let out a low groan as your slowly feed your cock into Mary's hungry sex, inch by magnificent inch. Mary howls in delight into the mattress beneath her as your fat cock brushes through the silk-like walls of her channel.

"You knew?" You just about hiss, hoping Marys own moans and the overwhelming pleasure are enough distractions to overhear your exchange with Leslie.

"Of course, You honestly think I couldn't recognise my gorgeous older sister?" Leslie whispers into your ear. "The same older sister I fantasise about from my late teens to this very day, ever since I walked in stroking that huge cock in the shower," Leslie continues to whisper, her lips kissing you on your neck.

"I had no idea," You groan louder than you meant as your find yourself suitably distracted by Mary's pussy, finally taking the full length of your cock.

"No idea about what?" Mary groans heavily.

"No idea that I'd enjoy fucking my Sister's fiance so much," You quickly cover, gently slapping Mary's ass.

"Mmmmm, I know," Mary hisses, "It's wrong, but that's making it feel even better," She pants heavily.

Leslie smiles at you before leaning into your ear once more. "There's a lot you don't know about me, my dear sister," She whispers seductively. "But now we've crossed that forbidden line, I can tell you so much," She adds, licking your ear in a teasing manner. "We can do...oh...so...much...more," Your Sister whispers breathily, emphasizing each word.

By now, you were fucking Mary with a fairly rapid pace, watching your thick length being repeatedly gobbled up by Mary's sweet silky-sex, coating your shaft in her delightful juices. You can feel your balls writhing and twitching as your sister cradles your weighty sack with a soft hand, massaging them while she continues to whisper dark, dirty fantasies she had about you when you were growing up together. Which, in combination with Mary's sexy moans and groans of pleasure, was quickly working you into a frenzy.

"My favourite dream," Your Sister pants in your ear. "Was taking the place of one of those lucky girls you'd bring back home after a night out drinking," She continues, while you begin to feel your cock start to harden inside of Mary's slick channel. "You'd be too drunk to notice them leave or that it wasn't the same girls sneaking back into your bed," Your Sister continues.

"Fuck," You groan, feeling your cock throb.

"I'd take deep breaths as I sneak in, savour that heavy aroma of sex, your cum and that lucky sluts," Your Sister pants, moving herself behind your to switch ear, you feeling her nipples dragging across your back. "I'd lift the covers and slide under them and over to you, feeling the wetness of the sheets beneath me, giddy at the thought that my own juices would soon add to them," She continues, as once more you feel your cock jerk deep inside Mary's pussy.

"Fuck, don't forget to pull out," Mary warns, through heavy moans, her own intense orgasm rapidly approaching.

"I'd reach over and begin to stroke your cock, finally having my hands on your wonderful gift," Your Sister whispers, using her free hand to tease the base of your shaft. "I'd get you horny and ready for what you'd think was just round 2," She adds with a flirty giggle. "You'd groan in agreement and roll over to fetch a condom, but I'd stop you, telling you I was feeling extra naughty now," She continues, and you feel your balls begin to churn as the overbearing heat and pressure inside of you begins to reach boiling point.

"Shit," You groan, your cock giving Mary another heavy warning twitch.

"Just a little longer, please Claire, I'm almost there," Mary pleads as you pound away from behind.

"You wouldn't take much convincing, all too happy to fuck your slut bareback, eagerly sliding that thick cock and popping my cherry in one thrust," Your Sister coos. "I'd be lying beneath you, leaving scratches in your back as your pound me, while I lie there wondering if and when you'll notice who you're fucking, and if that'll stop you," She teases.

"Ahhhhh," You groan, feeling yourself teetering on the point of no return.

"I'd wrap my legs around your back and my arms around your back, clinging to you, refusing to let you go," Your sister pants. "Howling in pleasure as you fuck me hard, waiting for that moment where you can't hold back anymore," She adds teasingly, giving your balls a playful squeeze. "Until you unload into my unprotected pussy, pump me full of your hot cum, cumming hard as you blow your load in me, possibly knocking me up on my first time," Your Sister growls.

Mary lets out a cry of pleasure; her slick walls tighten their grasp around your thick throbbing length, flexing around the majestic muscle, trying to pull you in deeper. You can already feel your hot, potent cargo pumping its way through and up your shaft while your Sister Leslie continues to whisper her dark fantasy into your ears. Focusing her story on how you'd unwittingly inseminate and impregnate your own sister.

It was too much to handle, and you let out a primal groan, Your sister pressing herself into your back, forcing you as deep as you could go into her Fiance as you begin to cum hard. Mary lets out an alarmed whimper between her heavy moans of pleasure as she feels your cock throb and pulse, the sweet heat of your thick super spunk rocketing into her defenceless pussy. You howl and shudder as you cum hard while Leslie kisses your neck and strokes your body as you empty yourself into her wife to be.

Once Mary had come down enough from her orgasm, she whips her head around, ready to berate you for cumming inside of her. However, when she sees Leslie behind you, she finds herself lost for words, a mixture of fear and shock robbing her of words. "It's ok, Love; I told her to cum in you," Leslie says in a sensual manner, stepping away from you and over to her Fiance. Mary noticing now that Leslie was also naked.

"Babe?" Mary asks in confusion.

"Well, I didn't want to be the only one carrying a little early wedding present on our big day," Leslie says with a soft laugh.

"But...." Mary stammers, gesturing to you in confusion.

"You should know better than anyone about my kinky fantasies about my Sister," Leslie explains, turning to face you with a grin. "I make her call me Sis when she fucking me with a strap-on," Leslie explains with a giggle.

"I'm so confused," Mary stammers, rolling onto her back and surveying the creamy mess you've made of her pussy. "Fuck, that's so much cum," She groans.

"Oh, it's going to get a lot more before we're done today," Leslie giggles, leaning down and scooping up some of your cum leaking from Mary's sex and eagerly popping her sticky fingers into her mouth. "Mmmmm, taste's wonderful," Leslie coos in a sexy tone, sensually licking her lips. "But I can't eat too much until it's done its job and made a baby," Leslie adds, leaning over Mary and kissing her on the stomach.

"Babe, I thought you wanted to wait before either of us had kids," Mary asks hesitantly.

"Until we found the perfect donor," Leslie clarifies, "And my Sister fits that bill perfectly," She adds, glancing back at you and throwing you a wink.

"But what about you?" Mary asks, still trying to process all of this.

"Claires going to knock me up too, cheeky minx might already have done at my party," Leslie confesses with a giggle.

"Wait, you were the stripper she fucked?" Mary gasps in surprise.

"Guilty," You reply with a nervous laugh.

"Look, I know it's a bit unorthodox, but it's this wild side of me that you fell in love with," Leslie explains. "We both wanted kids eventually; I just moved up the time scale," She adds.

"Did you plan this?" Mary asks

"No, I don't know if the stars aligned or if there's some wicked mastermind pulling strings, but Claire turned up at my party, didn't think I recognised her and fucked me hard in front of all our friends," Leslie explains.

Mary rubs her head and tries to take this all in, while your Sister pulls her Fiance into a tight embrace. "This is so fucked up," Mary says, shaking her head.

"But it's kinda hot, though, right?" Leslie replies with a giggle.

"Incredibly," Both you and Mary reply, the pair of you meet eyes and laugh, laughter that fills the room, with Leslie joining in until all three of you couldn't laugh anymore.

"This still feels so weird," Mary explains.

"Don't think about it so much then," You offer with a smile.

"Babe, both of us might carry my Sister's Baby, but they'll both be our Children," Leslie says with a big smile. "A family of our own," She adds. "Just like we dreamed of," She concludes.

"But where does Claire fit into all of this?" Mary asks.

"I was thinking the cool Aunt," You reply with a smile, that try as she might, Mary can't help but find infectious.

"Don't forget Sister with Benefits," Leslie adds with a grin.

"Really?" Mary asks, raising an eyebrow.

"Why not? You'll be my Sister too," You reply, putting a hand on Mary's leg. "Maybe my wedding present could be some form of intergalactic booty call either of you can make," You offer with a grin. "I might also have another friend like me who'd love to get in on this," You offer with a grin, thinking back to Amanda for a moment.

"Mmmmm, a threesome with a futa, with the possibility with a foursome with two futa's," Mary groans.

"Sounds perfect," Leslie replies with a grin.

"Well, we still have the rest of the night; how about I give you both a demo of what those threesomes could be like?" You ask with a wicked grin.

The next several hours turn into a blur of pleasure for all three of you as you act out several fantasies of Mary and your Sister until all of you are too tired to continue. Then, finally, the three of you fall asleep in a thoroughly stained bed, with you falling asleep safe in the knowledge that your Sister will happily keep the baby you gave her at her bachelorette party and get a bonus point with Mary. With the bonus of plenty of future taboo fun with the pair of them in the future.