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“You’re being such a good boy for me.” says my girlfriend from behind me, one hand caressing my belly, and the other jerking me off, “Mfh~, poor baby… don’t worry, while I’m here everything is going to be alright.”
I whine helplessly as my belly gurgles loudly, swelling continuously. She’d only implanted her latest experiment half an hour ago, but it already feels like I’ve got an entire basketball in me. My asshole, or I guess it’s now a pseudo-cloaca thanks to her, leaks thick globules of goo onto her leg. I buck my hips into her hands, groaning as my senses are assaulted from all angles. She goes faster, cooing in my ear. The growing pressure in my new womb is pressing against my prostate, and the subtle movement from the creature inside slithering against it is making me see stars. I can’t think. The lower half of my belly continues to bloat, and soon it’s pressing onto the top of my dick.
“Oh my gosh, you’re swelling so nicely...” she whispers. I moan softly, as if trying to contain the noise.
She pulls my cock downward, and then releases it, letting it thud into the bottom of my tight stomach. Every time it twitches I can feel it press against me, and gradually get pushed down more and more as I expand relentlessly. A mass presses against my muscle wall, the large distension bulging out my side. I groan as it glides around, eventually pressing into my straining erection. No sooner is it there though, it sinks into the churning depths of my womb. My girlfriend’s hand that was previously rubbing my aching belly comes up to my neck and gently pulls me backwards towards her, so now my head is resting on her shoulder and my belly is pressing out over my kneeling legs.
“Please… ah-umph~” I barely make out.
She leans forward, her hair tickling my face and chest, and gently strokes the shaft of my penis with the tips of her fingers. I’m so so close… if only she’d just–. The mass returns, but instead of bulging me out it presses directly into my prostate. I gasp. My entire body clenches as thick ropes of cum erupt out of my pulsing dick, all the while whimpering like a pathetic puppy. I grind my slick, sensitive asshole on her leg as the euphoria washes through me. It’s intense, and it’s exacerbated by the feeling of my abs trying and failing to tense around the tight swell of my womb. Eventually, mercifully, the climax abates, but the pressure inside does not. Whatever’s filling me doesn’t seem to care that I’ve just finished, because after being rudely squeezed it redoubles its efforts and starts growing more rapidly. I start panting, one hand pressed against my still tightening belly as my womb shoves my other organs out of the way. Oh fuck yessss. I whine softly in my girlfriend’s ear, who hasn’t noticed and is instead cleaning her hands with a teatowel.
“Yes, you’re such a good boy~. I love you so mu– oh fuck.”
Her eyes go wide when she turns her head back to me. I’ve almost doubled in size, and with a menacing gurgle and a thud, my navel pops out. She scrambles out from behind me, laying me down on my side. I can’t really think right now, but I’m sure nothing is wrong. She loves me, and she said she’d take care of me. Also the intense pressure is making me aroused again, despite coming just a minute earlier.
“J–Just wait here, I’ll be right back, I promise!” She looks at me with wide worried eyes, and rushes out of the room.
I can feel the clear, slick goop that’s now continuously leaking from my butt coating the inside of my thighs, which I rub together in delight. My dick is now erect again, and barely able to get up due to my massive swollen belly being in the way. I try to reach it to masturbate, but I’m just too large. I move my hips slightly and moan as my penis glides across the surface of my bulging stomach. It’ll have to do. With little thrusts I fuck my own belly, moaning into the sheets, the sounds mostly drowned out by the large gurgles from my abused womb. I open my eyes to see if she has come back, but all I see is a wall of skin obscuring the door. I’m bigger than a beach ball. Something deep in my mind is trying to set off alarm bells as a snake-like bulge as thick as a leg moves across the surface of my belly. I pay it no mind, and instead keep humping myself, the combined feelings of pressure and movement from inside me clouding all judgement. I hear a rapid thumping as my girlfriend rushes back into the room.
“Ok ok I’m back–holy shit–uuuh ok… alright I need you to get onto your hands and knees NOW.”
I groan in complaint as she shoves her hands under my side, and huffs in effort to lift me up. I roll over and lean briefly on my belly, then push up from the bed. It does not leave the surface. The sudden change in gravity makes the creature inside squirm, bulging me out randomly. I whine and shiver uncontrollably in overwhelming pleasure. I can hear my girlfriend fumbling with a bag I’ve seen in her lab, pulling out various vials quickly, reading the label, and discarding them.
“The failsafe gene must’ve completely messed up or mutated out, so it’s not stopping at all. It’s probably also secreting that muscle relaxant and aphrodisiac combo I was toying with, do you feel lightheaded or– oh yeah never mind.” she says looking into my unfocused eyes. I probably have an expression of pure unbridled lust on my face.
My belly presses against the front of my thighs and into the bed as it continues to swell. I don’t have to buck my hips anymore, just running my hand over my belly is euphoric. I bring both hands to my sides and feel the writhing inside me… fuckkkk it’s so good. Wait, both hands? In my clouded mind I at least have the mental capacity to realise that that’s strange. My giant belly burbles under the strain of my weight, which I faintly realise is now holding me up. I reach down to the bed to steady myself, but I can’t reach anymore. I whine helplessly as I feel my knees start to lift up from the bed, trying to get my girlfriend’s attention again.
“I’m going as fast as I can… FOUND IT” she brandishes a small clear vial, and promptly loads it into an injection gun. “Once this is in you it’s going to induce birth immediately. Brace yourself!”
She presses the nozzle against the side of my churning belly, and pulls the trigger. I don’t even register the pain. Almost instantly, all activity inside me ceases. The stillness is almost strange, only the pulsing of my dick against me and my racing heart is active. I try to lean back to get my knees back onto the bed, but I’m literally stuck on top of my own stomach. A long, slow, deep burble ripples inside me, breaking the silence. I look at her and whimper, a thread of dread peeking through the euphoria. The movement inside starts up again, but more lethargically than before. It speeds up, thrashing faster and faster. I groan and grip my sides as it churns relentlessly, abusing my guts. My girlfriend clambers behind me, holding my hips. She's about to say something when suddenly a vicious contraction washes through me. I squeal, and a huge squirt of the nutrient rich mucus from inside my womb rushes out of my asshole and slams into her, coating her face and chest. She splutters, trying to wipe it off as more weaker pulses escape from me. I whimper as I feel the creature find my cervix, and press against it. My entire belly surges backward, pushing my dick out of the way. I close my eyes and groan in response to the assault, my cervix is slowly, achingly, dilating to release the creature trapped inside my womb. With a heavy plop its entire width squelches into my passage, and rapidly rams against the inside of my pulsing anus, more thick fluid gushing out. I come again – I can’t help it. My asshole slams shut in front of the worm, barring its escape while I whine like a dog. It wriggles inside me, right up against my prostate, just encouraging the blinding orgasm to continue. I can feel only little dribbles of cum this time running down the taut skin of my restless belly, due to my previous orgasm. My twitching dick strains just as much as before though. The sheer power of the climax is agonising, but after an age I shiver, the final pulse of cum dribbling out of me, and relax. Immediately the creature seizes the opportunity and rushes partway out of me, stretching me so wide it feels like I’m being split down the middle. My girlfriend yelps, and promptly grabs the writhing worm, which is about as thick as my own calf. She tugs, and I gasp as I feel it slide out, rapidly relieving the immense pressure from my belly. I drop down back onto my hands and knees as its pulled out of me, subtle ridges along its length plop again and again, sending sparks across my skin. I groan as a final contraction clenches my abdominal muscles, squeezing the rest of the creature out with a wet slurp. I immediately flop onto the bed, completely spent. I can hear my gaping anus attempting to regain its shape; It clenches with a wet fart sound, releasing a dribble of goo. All I can do is pant as I watch my girlfriend through bleary eyes wrestle the creature on the floor, attempting to get it into submission, but failing completely. I did good… I think.