You breed Samantha and give her the last nudge she needs to becoming a permanent futa

A woman of your word, with Samantha's submission, you reach down and slide her shorts down revealing the painfully swollen cock to the crowd. You wrap your fingers around the swollen member and begin to pump it rapidly with your hand. It doesn't take you long to get Samantha to cum, with how close she already was before you got her to surrender and unstable gene-moded hormones running rampant in her body. You feel the impressive mass of Samantha's beast harden and twitch in your grasp before it pulses and begins to erupt, the crowd going wild with each rope of cum that shoots from Samantha's cock.

With the crowd still cheering you step back and throw your hands over your head in victory, while two masked members of staff from the gym make their way down to the ring to prepare for the main event. Samantha hardly resists, still riding the dizzying high of her orgasm as the staff strip her naked with the exception of her mask and place a suspensor cuff around her wrists and ankle. One member of staff hands you the control wand for the high-tech bondage devices. With a simple press of a button, Samantha would be completely at your mercy ensuring she couldn't try and brute **** her way out of your claiming your prize.

You walk around the ring to face Samantha, while the staff mount a frame with various beams that you can attach the high-tech bondage restraints to, to allow you to freely manipulate Samantha into any position you could want. You'd still be limited by gravity and your own and Samantha's flexibility, but it should mean you can provide the unseen audience with a good show. You smile at Samantha as you begin to undress, making sure she gets a good long look at the goods you'd soon be breeding her with.

"Such a wonderful well-sculpted body," You purr running your hands over Samantha's athletic frame. "Can't wait to ruin all that hard work by knocking you up," You add with a sensual giggle.

"Just get on with it," Samantha growls bitterly, trying hard but unsuccessfully to not stare at your thick length and the weighty balls, your sack nice and plump with virile super seed.

"Oh, like you didn't tease and torment all those women you bred?" You reply with a teasing tone. "Oh no, I plan on having a lot of fun with you," You continue in your teasing tone, reaching forward and taking hold of the gene-mod vial still attached around Samantha's neck.

"Hey don't touch that," Samantha complains, although she can do little but stare in anger as you effortlessly lift and remove the gene-mod vial from its attachment.

"I believe the terms of our fight was I could do anything I wanted," You reply with an evil smile. "So this was what you were planning on taking to ensure I would be walking out of here with a womb full of your healthy swimmers," You muse aloud, examining the vial in your hands.

"Why don't you release me and find out," Samantha growls.

You smile and slide your hand down Samantha's body until your soft fingers brush against her cock, the half-hard member still slightly sticky with the orgasm you promised in exchange for this victory. Even after cumming so soon, you can feel the slumbering beast stirring back to life at your light touch. "We'll make a proper futa out of you yet," You whisper to yourself while taking a moment to admire the equipment gene-modding had given Samantha.

"Stupid thing got me into this mess," Samantha grumbles, chewing her bottom lip to suppress a soft moan as your fingers continue to caress the athlete's sizeable shaft.

"Yeah, bet they never warned you about that when you were buying the stuff," You reply with a grin. "Admittedly mine never got me in quite this predicament, but let me tell you puberty was a real bitch with both sets of hormones running rampant," You say softly, slowly stroking Samantha's cock to full size.

"Lucky you," Samantha grunts, this time a hint more of the pleasure she's currently feeling escaping her lips than she means.

"Speaking of luck, you got pretty lucky with how gene-mod came out," You explain with a smile.

"Funny, I don't feel all that lucky at the minute," Samantha complains. "Stupid thing isn't supposed to even be out until I use that vial," She adds currling her toes as you continue to lightly stroke Samantha's rapidly swelling shaft.

"Personally I don't know why you'd ever want it to be temporary," You reply in a soft sensual tone, teasing a single finger up the entire length of Samantha's cock.

"Well, my scholarship for one, then there's my Sisters in the sorority, oh and thirdly I don't remember it being any of your damn business so how about we drop the routine and just fuck me and get this over with already," Samantha growls defiantly in a low tone.

"Ah yes, I'm sure your Sorority sisters treat you equally, definitely don't talk behind your back and only ask you to help out when anything needs lifting," You reply with a soft whisper, your hand still teasing the restrained athlete shaft to keep her horny.

"Well maybe they do, but again I don't see how any of this is relevant to you fucking me," Samantha growls, clearly your line of inquiry striking a raw nerve.

"As for your scholarship, You'll be able to get one from the colony growth fund once I knock you up, silly," You reply in a teasing tone. "Sure they might make you compete in the omni-sex leagues once you return after maternity, but trust me when I tell you that the lockerrooms in those leagues are much more enjoyable," You reply with a casual tone, dropping the teasing nature of your speech for a moment to seem more convincing.

"I have heard some interesting rumours, I'll admit," Samantha agrees in a low tone.

"Good, then that settles it, we'll add another layer of fuck to my victory," You reply with an evil smile. "A game within a game as it were," You add with a giggle as you look at the vial you took from Samantha to double-check it'll work how you hope it will.

"No way, this wasn't part of the deal," Samantha replies her eyes widening as she sees you moving the vial next to her now fully erect cock.

You flash Samantha another wicked smile as you tease the gene-mod vial across the swollen shaft of Samantha's impressive cock. Honestly making her a full-time futa, you were doing her and many lucky people to experience her cock a favour. "Funny I recall the terms are I could do whatever I want to you," You reply with a giggle. "Besides, I'm giving you a chance to play for it, not just using this and then claiming my prize," You add in a sensual tone.

"Isn't it bad enough there's a chance I'll end up pregnant?" Samantha complains.

"Oh your pregnancy isn't a chance, it's a certainty," You reply with an evil smile, leaning in right next to Samantha's ears for the next part. "I've got the black-market mods to all but guarantee it," You add in a whisper, moving your hand off her cock for a moment to stroke her muscular abbs above where her womb would be, before moving it back to her twitching cock. .

"Lucky me," Samantha groans, although despite her protest

"Oh, don't be so glum, maybe I can point you in the direction of someone who can hook you up, should you lose the second game," You add with another whisper, the hand you were happily teasing Samantha's cock to full hardness with, suddenly wraps around the thick shaft and you begin to stroke it.

"What second game?" Samantha whimpers, your expert hands twisting and squeezing her cock in all the right ways to make her squirm in pleasure.

You ignore the restrained athlete's question, focusing on working her wonderful shaft, gliding your thumb in small circles beneath the swollen crown of Samantha's cock. "Give that beast you're packing as much punch as mine," You continue flashing Samantha a conspiratorial smile.

"Tempting," Samantha groans in reply, unable to do much else other than endure the pleasure of skilful digits sliding up and down her thickness.

"Just think at how much sweeter victory will feel, knowing your opponent will have a living breathing reminder of your dominance over them," You purr in a low tone. At that comment, you feel Samantha's cock throb and twitch heavily in your hand and you knew that it wouldn't be a particularly hard adjustment for Samantha when you make her a permanent futa.

"Oh fuck," Samantha groans with a soft whimper of pleasure accompanying it, her cock twitching and throbbing in your grasp as she nears her point of no return.

"So here's the second game," You say in a loud theatrical manner, leaving long gaps between your words as you stroke Samantha closer and closer to her next orgasm. "If I can make your cock cum just three more times before I'm breeding you, then I give you this mod which will make your change permanent," You explain, mostly for the audience's benefit, holding up the vial you took from Samantha.

You know enough about the substance in the vial that with the physical changes already present the mod will move onto the second stage of stabilisation, locking the new physical changes in place. The crowd cheers at the revelation, although you suspect part of that cheer is the prospect that they might soon see you fucking a baby into Samantha.

"Wait no, you can't do that," Samantha cries, trying in vain to fight against the restraints, her cock still throbbing and twitching in your hand. Samantha's cries of frustration quickly change to groans of pleasure, followed shortly by a louder singular groan of release. Her cock throbs and pulses as it erupts in your hand, thick pearlescent strands of seed tumble through the air before splattering the floor of the makeshift ring.

"One down, two to go," You say triumphantly before you start to adjust Samantha's body into a new position. "You're going to need to try harder than that if you just want to walk out of here with my kids to raise," You add with a wicked grin. The position you move Samantha into is a slightly elevated missionary, so she's suspended at a 45-degree angle with her legs above her head.

"Kids?" Samantha asks wearily, still a little woozy from the post-orgasmic haze.

"Yeah, I'm not sure why, but I just have the feeling it'll be twins, I'm fucking into you," You reply with a giggle, taking hold of your thick length and tapping it against Samantha's slick lower lips.

You're not sure if Samantha even has a retort for you, if she has any words they're immediately drowned out as your press the swollen tip of your cock between the hot wet folds of Samantha's sex. The lips of her juicy pussy part effortlessly around your thick shaft, inch after wonderful inch of your own beast sinks deeper and deeper into Samantha's love canal. You bite down on your lower lips as wave after wave of pleasure crashes over you, the sensation of Samantha's silky warm embrace of your fertile fuckstick, driving you wild.

You have to take a moment to acclimatise to the raw dizzying amounts of pleasure Samantha's sex is giving you once you've bottomed out in her. The tip of your potent pounding instrument presses into Samantha's cervix, your nanite-laded pre-seed leaking freely from your shaft. Once done with doing what little there is to be done to bring Samantha to peak fertility, given her exceptional healthy lifestyle, they'd then busy themselves with stabilising the gene-mod cells.

Even if you somehow fail to make Samantha cum twice more, there's a reasonable chance your nanites might do the job anyway, after all, they are programmed with repair and enhancement work to facilitate peak baby-making conditions and technically Samantha's cock does fall under that remit. Although it is merely a theory at this point, one Dr. Charms can test when you point Samantha in her direction to get a dose of the slightly more refined and she's developed from all the data you've provided so far.

Once you feel like the slick warmth of Samantha's tight pussy won't cause you to lose control and cum too early, you begin to slide yourself back and forth within the tight embrace of Samantha's sex. The restrained athlete is soon howling in pleasure, her eyes rolling back and her toes curling as each pass of your delicious dick brushes against all the sensitive nerve clusters nestled deep inside her body, including a few she wasn't aware of just yet.

Lost in pleasure, Samantha doesn't notice at first, the strange heat and pressure building just beside the more familiar sensation of enjoying a good dicking. It isn't until she feels the sticky droplets falling onto her face, which causes Samantha to open her eyes and look up, that she realises she was wrong about quite a few things. Firstly Samantha was wrong to assume that this modified missionary position was just to get gravity to assist your seed to flood her womb. Secondly, She was wrong to assume that having cum twice with her cock, she'd be spent and therefore didn't have to worry about her cock being made a full-time addition to her body.

You can't help but smile when you see Samantha's eyes go wide as you fuck more precum out of the Athlete's once more rock-hard cock. You can't help but feel a sense of glee as you watch the metaphorical cogs turning in Samantha's mind and the realisation hit her hard, that yes you could absolutely make her cock cum by just fucking her pussy. You pick up your pace and begin to really rail Samantha, eagerly anticipating the moment she can't help but cum.

Wonderful minutes melt away, you watch Samantha desperately trying to resist the pleasure, her cock leaking a steady trickle of precum by this point as you continue to stimulate all her futa weak points from within. Much like how the prostate in a man can be stimulated through anal fun, the futa's can be stimulated via both holes. With extremely sticky but fun results if it's stimulated via both holes at the same time. Samantha will have all this fun stuff to learn, but right now the lesson comes in the form of being completely powerless to stop you from fucking her one orgasm close to making good on your promise.

"Mmmmm, someone looks like they're enjoying this," You grunt in a teasing manner, feeling your own balls churning as hard as Samantha's are the pair of you moments away from orgasm.

"No, can't hold back," Samantha whimpers, her cock twitching and lurching as you continue to fuck her mercilessly.

With a cry of equal parts pleasure and frustration and defeat, Samantha begins to experience what you assume to be her first full-body orgasm as a futa. The sweet tight folds squeeze your cock impossibly tight. Her cock begins to throb and pulse wildly, and her cum fountains out in thick sticky jets of cum spray upwards before raining down onto Samantha's body & face, for added humiliation.

"Fuck that's hot," You growl as you thrust yourself forward and let Samantha's pussy milk your cock to completion.

Your cock throbs and pulses as your thick super sperm races up the length of your rockhard cock. There's the sweet tickling sensation, much like the moment when a ship leaves the gravity of a planet before the artificial gravity kicks in, where your sperm idles waiting for the pressure to build before it erupts like a volcano. Thick sticky strands of your potent payload race straight through Samantha's cervix and splatter against the back wall of her womb. Your cock continues to throb and pulse, the overspill leaking obscenely around your shaft.

Once you've come down from your orgasmic high you slowly slip yourself free from Samantha's body, with some ****, but you'd have your chance to fuck Samantha some more, once your final performance was done.

"And that's two, one more and this gets to stay," You say triumphantly, tapping Samantha's spent and stick cock for emphasis.

"No, we're done, I felt you fill me up," Samantha pants, looking up at you with one eye as the other is shut due to all the cum coating it.

"Oh, you should know by now that we futas aren't just done after one orgasm," You reply in a teasing tone.

"You can't be serious," Samantha complains.

"You really do struggle with the whole, I can do anything to you, part of this arrangement aren't you," You reply with a laugh. "Still If it makes you feel any better, I'll give you a little bonus," You continue, once more manoeuvring Samantha into a new position and even taking time to wipe the cum coating the closed eye. Samantha is now standing upright back ever so slightly arched.

"Fine what is this bonus," Samantha groans.

"Well seeing as you wanted to breed me as you admittedly limited prize, I'm going to give you that chance," You say with a grin.

"You are?" Samantha replies in a moment of genuine surprise, her lifeless cock"Yup, I'm going to use my pussy to try and get you as close to cumming as possible," You explain with a smile. "Maybe I misjudge and you get to fill me with some of your cum, maybe I judge correctly and your cum shoots harmlessly all over my ass," You continue with a grin, walking around to the front of Samantha and wiggling your ass enticingly for her.

"So either way I cum and have to keep this thing," Samantha groans

"Hey, at least I'm giving you a shot at something you want, nothing stopping me fucking that load out of you and making you swallow it this time," You reply with a grin.

"Fine, but if your ass ends up knocked up, you can't come crying to me," Samantha says accepting her fate and at least relishing a chance to get a little even.

It doesn't take long for Samantha to get hard again, you turn to face her wiping her cock clean of the remnants of her earlier orgasms, then begin to stroke her cock, before moving your own in above it to get a fair comparison of the two. While yours is slightly longer, there's a little more girth to Samantha's. At some point, you decided to try stroking both your cock and Samantha's and at the same time, the feeling is a little strange if not too unpleasant, your precum making a pretty decent lubricant for the job.

Still, once Samantha is good and hard for you, you turn around and slowly shuffle yourself back into place, you feel the bulbous head of Samantha's cock pressing against your lower lips, the pressure mounting for a moment before the part and you begin to take Samantha inside of you. This wasn't part of your initial plan, rather something you came up with on the fly, but as you feel your lower lips stretching around Samantha you are glad it's a change you went with. Besides the risk should be minimal, just your standard odds against nature. Although you catch yourself making the assumption you'd be letting Samantha cum inside you, rather than hopping off when she's close to cumming.

Still, it's all too easy to get lost in the pleasure of the moment, you close your eyes and allow the flood of pleasure to drown your mind, indulging in the sweet sensation of having your depths plunged by a fellow futa. You continue to rock yourself back and forth on Samantha's cock, using the frame as leverage to do so. You feel your balls churn and writhe as Samantha's cock hits all the same weak spots you were hitting in her earlier. If nothing else this little risky game would ensure you have a full heavy load to shoot inside Samantha when you're done here.

As the minutes melt into one, you lose track of time and the moment, until you feel Samantha's cock twitch deep inside of you. At first, you feel a wave of panic cut through your mind before you rationalise it. One twitch just means Samantha was enjoying your pussy, and how could she not, besides Samantha didn't sound like she was close, no you still have plenty of time to enjoy this.

Little did you realise that deep in the fog of lust and pleasure, you had missed the several smaller twitches Samantha's cock made, nor did you realise that Samantha's face was one of pure concentration. A laser-like focus to keep Samantha from betraying just how close she was to filling your sweet defenceless pussy with a thick batch of her own baby makers. This is why you keep going, allowing yourself to be lost in pleasure once more until it's too late.

You first realise your mistake, when you feel Samantha's cock begin to throb and pulse deep inside of you, a warm wetness spreading deep inside of you as Samantha finally breaks concentration to let out a triumphant grunt. "That's it take my fucking seed you overconfident slut," Samantha groans as she fills you with her orgasm. You know you should hop off, that there was absolutely a difference between letting Samantha half-fill you and fully fill you with her cum, but you decide to let her have her little victory.

Once Samantha is done cumming inside you, you pull forward and ensure the crowd get a good view of the creamy mess of your pussy. "Well I am a woman of my word, but now that you've had your prize, it's time for me to claim mine," You say with a smile, taking the Gene-mod vial and injecting it into Samantha's upper thigh. All the prior micro-dosing, and the more recent unwittingly heavier dosing combined with your nanites, all get to work on cementing the cells and updating the DNA strands responsible for cell regeneration. Samantha's cock and all its accompanying changes were here to stay this time.

"Worth it?" You ask Samantha in a low tone.

"Totally worth it," Samantha replies in an equally soft tone.

"Good because I've got something I'd like to discuss with you, that I think you'll be very interested in, some opportunities to put those futa assets to work," You whisper in a serious tone.

"Mmmm, we'll talk in the locker room," Samantha agrees. "But first you're not leaving this ring until you drained every drop from those balls inside me," She adds with a grin.

Never one to shy away from a challenge you spend the next hour creaming Samantha's pussy, packing her womb full of your potent super sperm and even making good on your promise that you'd be knocking Samantha up with twins.