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The Experimental Endeavor (F)

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A woman and her girlfriend have a stale sex life and the girlfriend clearly isn't satisfied with toys for penetration; the woman decides to get a new experimental injection to grow a penis. Not only does it work, it also has other unintended side effects like breast growth. The girlfriend loves it, but wants even more.

Chapter 43: The Breaking Point

The sound was a wet, yielding pop, like a cork pulled from a deep bottle.

It wasn’t loud. But in the sudden, strained silence of the room—broken only by ragged breathing and the slick grind of flesh—it was catastrophic.

Clare felt it happen. A final, intrinsic barrier, one the machine had only bullied, gave way. The monstrous, flaring crown of Evie’s cock, which had been applying a constant, spreading pressure, suddenly sank through. The sensation was not of tearing, but of profound, impossible opening. A gate she hadn’t known was locked swung inward into a dark, private vault.

Her entire body seized. Every muscle from her pelvis to her throat went rigid. A choked, airless gasp was all she could manage. Her eyes, wide and unblinking, stared down at Evie, who looked back with a mirroring horror. The feeling was beyond pain, beyond pleasure. It was anatomical revision. She was being fucked in a place that wasn’t meant for fucking.

“Oh, god,” Clare finally whispered, the words a thin stream of sound. “Evie… you’re in my womb.”

The words made it real. Evie’s hips, which had been moving in shallow, desperate jerks, froze. She could feel it. The head of her cock was encased in a new, tighter sheath of clenching, molten heat. The contours were different. Deeper. It was a wet, suckling embrace from the very core of Clare. The sensation was so intense it bordered on violence.

“I… I can feel it,” Evie rasped, her voice breaking. “Clare, I’m sorry, I’m—”

“Don’t you fucking apologize,” Clare hissed, her nails biting into Evie’s stomach. A wild, triumphant light was in her eyes, blazing through the tears. “Do you have any idea… any idea what this feels like?” She began to move again, a slow, grinding rotation of her hips. The movement made the lodged head twist inside that deepest chamber. Clare threw her head back and screamed, a raw, continuous sound of victory. “It’s full! I’m finally full!”

Sophie, still straddling Evie’s face, felt the shift. She lifted herself slightly, looking down at Clare’s enraptured, broken expression, then at the obscene join of their bodies. The sheer scale of it, the dark poetry of that penetration, sent a fresh jet of arousal soaking her thighs. “Fuck her,” Sophie urged Evie, her voice a hot whisper. “She can take it. Look at her. She was built for it.”

Evie was trapped. Clare’s internal muscles were milking the trapped crown, a rhythmic, possessive suckling that drove all rational thought from her head. Her own insecurity, her fear, was being burned away in the furnace of Clare’s absolute, devouring acceptance. This was what Clare had needed. This brutal, beautiful fullness.

With a guttural sound that came from a place older than language, Evie began to thrust in earnest.

They were shorter, deeper strokes now, limited by the new, profound depth. Each drive forward seated the massive head firmly back into Clare’s womb, a blunt, rearranging nudge. Each withdrawal stretched the ravaged channel of her cunt to a slick, glistening tightness around the monstrous shaft. The wet sounds were obscenely loud, a squelching, slapping chorus.

“Yes! Right there! Fuck, right there!” Clare chanted, her lawyer’s composure annihilated. She was a creature of pure need, her body bowed backward, her large breasts swaying, nipples hard. “Give it to me! Fill me up! I want to feel you come in my fucking womb!”

The demand was a lightning strike. Evie’s control shattered. Her thrusts became erratic, brutal piston strokes. The bedframe slammed against the wall with a sound like gunshots. The medical journals on the nightstand vibrated onto the floor.

“I’m gonna… Clare, I’m gonna—” Evie warned, her voice a ragged sob.

“Do it!” Clare shrieked. “Paint my fucking insides! I want to feel it for days!”

The orgasm that ripped through Evie wasn’t a release. It was a cataclysm. Her body locked, every corded muscle in her neck and back standing out. A roar tore from her throat, raw and inhuman.

Inside Clare, it was a volcanic eruption. Evie’s cock pulsed, not in spurts, but in a seemingly endless, hot flood. Clare felt it jet directly into her womb, a scalding, claiming rush that expanded her from the inside out. The pressure was immense, a bloating, stretching fullness that went beyond anything the machine or the previous growth had achieved. It was a geyser, and she was the basin it filled to overflowing.

She came again, her own orgasm a silent, breathless convulsion, her cunt clenching in frantic waves around the pumping shaft, milking it for every drop. Her vision whited out. She was nothing but a vessel being used, filled, and finally, satisfied.

It went on for a long time. When Evie finally collapsed back onto the soaked sheets, spent, her cock—still semi-hard and obscenely large—slid from Clare with a wet, heavy sound that made Sophie whimper.

Clare crumpled onto her side, her legs trembling uncontrollably. A slow, thick trickle of white immediately began to seep from her, pooling on the sheet beneath her. She felt hollowed out and simultaneously, impossibly full. The ache was profound, a deep, bruised sensation that radiated through her entire pelvis. She loved it. It was a brand.

Evie lay on her back, gasping, the reality of what had just happened crashing down. She looked at her cock, which even flaccid was the size of her former erect self, a heavy, veined thing lying against her thigh. Horror and a sick, thrilling pride warred in her chest. She had done that. She had given Clare that.

Sophie slid off Evie’s chest, her face flushed. She knelt between Clare’s splayed legs, staring with hungry fascination at the slack, dripping opening. She touched Clare’s inner thigh, which was slick with sweat and come. “Look at you,” Sophie breathed. “You’re ruined. Absolutely ruined.”

Clare managed a weak, triumphant smile. “It was perfect.”

Evie pushed herself up on her elbows. The movement made her new weight shift uncomfortably. “Clare… are you… did I hurt you?”

Clare turned her head, her blue eyes meeting Evie’s. The warmth there was real, but it was edged with a new, fierce possession. “You gave me what I needed. For the first time. Ever.” She reached a shaky hand out, not for Evie’s hand, but to curl her fingers around the base of her cock. The possessive gesture made Evie shudder. “This… this is mine now. You understand?”

Evie swallowed. The insecurity was still there, whispering that this wasn’t her, that this was a monster. But the look in Clare’s eyes—the awe, the satiation—silenced it. She nodded, mutely.

She nodded, mutely.

The silence that followed was thick, swollen with spent energy and the reek of their bodies. Clare’s breathing began to even out, her fingers still loosely circling Evie’s base. Sophie watched them, a strange, restless energy tightening her posture. She chewed her lip, her eyes flicking to the discarded syringe on the rumpled duvet near Evie’s foot. It was empty. Or seemed to be.

“That wasn’t the full dose,” Sophie said. Her voice cut through the haze, too bright, too sharp.

Clare turned her head slowly on the pillow. “What?”

Evie blinked, her mind sluggish. “What do you mean?”

“The syringe.” Sophie leaned over, snatching the plastic cylinder. She held it up. A tiny, viscous bubble of amber liquid clung to the inside of the plunger. “I didn’t inject all of it. I saved maybe… half. For me.”

Clare propped herself up on one elbow, wincing at the deep, satisfying ache between her legs. Her lawyer-brain, fogged by endorphins and profound physical reconfiguration, tried to engage. “For you? Sophie, what the hell? You want…?” Her gaze dropped to Evie’s heavy, transformed flesh. “You want one of those?”

A brittle laugh escaped Sophie. “No. I mean, fuck, look at it. It’s incredible. But I don’t think that’s how it works.” She rolled the syringe between her fingers, her expression turning clinical, fascinated. “I listened to you talk about Sharma’s machine, Clare. The speculum, the stretching. It wasn’t just about making a cock. It was about… potential. The serum isn’t a blueprint. It’s a catalyst. It reads the system. It amplifies desire on a structural level.”

With a terrifying decisiveness, she brought the syringe down. She didn’t aim for her thigh. She positioned the needle’s point directly against the swollen bud of her clit.

“Sophie, don’t!” Evie gasped, trying to sit up, her new weight awkward.

“It’s not so simple,” Sophie repeated, more to herself than them. Her breath hitched. There was fear in her eyes, but it was drowned by a voracious curiosity. “It’s not about getting a dick. It’s about becoming more of what you already are.”

She pushed the needle in.

The sound was a faint, wet puncture. Sophie cried out, a short, sharp gasp. Her back arched, but she held the syringe steady, depressing the plunger completely, injecting the concentrated remainder of Sharma’s serum directly into the most densely nerve-packed part of her body.

For a second, nothing. Then a tremor began in her thighs. It wasn’t the violent, body-racking transformation that had seized Evie. This was subtler, more insidious. A deep, buzzing heat radiated from the injection site, flooding her vulva, soaking inward. Her clit didn’t swell into a cock. It grew denser, harder, like a knot of live wires under the skin, thrumming with a current that made her teeth chatter.

“Oh… oh fuck,” she moaned, dropping the empty syringe. Her hands flew between her legs, not to pull away, but to press against herself. “It’s… it’s everywhere.”

The change wasn’t external. It was internal, a seismic shift in sensitivity. She felt her internal walls flush, not with arousal, but with a raw, hungry potential. The lips of her vulva felt fuller, heavier. A new, desperate emptiness yawned inside her, deeper than any she’d known, but it was an emptiness that craved not just filling, but overwhelming. Ruination. She looked at Clare, wrecked and leaking on the sheets, and a new, specific hunger unfolded in her gut.

“I can feel it…” Sophie panted, her voice trembling with awe. Her eyes, glazed and dark, locked on Evie’s still substantial semi-hardness.

Her eyes, glazed and dark, locked on Evie’s still substantial semi-hardness. "It's not about taking a cock," Sophie breathed, her voice thick with a new, understanding awe. "It's about being able to take that cock."

A low, wet sound, like a sigh, emanated from between her own legs.

Clare, pulling herself up with a wince, followed Sophie’s gaze downward. Her professional detachment, usually a shield, was gone. What remained was pure, clinical fascination mixed with a searing envy. She saw it first.

“Holy shit,” Clare whispered.

Sophie’s vulva was changing. The lips, already swollen from arousal, didn’t just part. They seemed to relax, then dissolve, then reform. The flesh unfolded, not like a flower, but like a complex, biological aperture. It lost all familiar structure, becoming a smooth, dark pink channel that appeared to deepen even as they watched. The inner walls glistened under the lamplight, not with ordinary moisture, but with a slick, clear fluid that smelled sharply of ozone and salt.

It yawned.

It was a conscious, muscular expansion, a silent invitation written in pulsing flesh. The opening widened far beyond any human norm, a smooth, hungry maw that seemed to promise no resistance, only enveloping, infinite depth. It was clearly, terrifyingly, readying itself.

“Soph, your… your clit,” Evie stammered, pushing her glasses up her nose with a trembling hand.

At the apex of that gape, Sophie’s clit engorged rapidly. It elongated, pulling taut from its hood into a hard, pointed nub of deep crimson, throbbing with a visible pulse. It looked less like a organ of pleasure and more like a tactile sensor, a fleshy needle. Then, a millimeter to the left of it, the skin rippled. A second, identical point of hard flesh pushed outward, emerging slick and complete. A third followed on the right, forming a tiny, perfect triangle of erect, sensitive nodes above the abyssal opening.

Sophie let out a shuddering moan, her hands spreading herself wider. “It itches,” she gasped. “It itches so deep. It needs to be scratched. It needs to be filled.”

Clare’s mind, reassembling itself, made connections with lightning speed. “The serum is substrate-literate. Sharma’s notes… it doesn’t impose a form. It reads cellular potential and amplifies it toward a desired function.” Her voice was a rushed, excited whisper. “Your desire wasn’t to have, Sophie. It was to accommodate. To be the ultimate receptacle.”

“I don’t want a dick,” Sophie confirmed, her eyes begging Evie. “I want to be a fucking hole. I want to be your hole. I want that thing,” she said, staring at Evie’s cock, which was stirring back to full, frightening hardness under their combined gaze, “to disappear inside me. I want to feel it in my stomach.”

The raw filth of the request, the sheer physiological audacity of it, sent a jolt through Evie. Her insecurity curdled, then metamorphosed into something darker and more possessive. Clare looked from Sophie’s transformed, gaping cunt to Evie’s monstrous cock. A slow, wicked smile spread across her sore lips.

“Prove it works,” Clare said to Evie, her tone a challenge and a gift. “She wants to be a vessel? Sink your goddamn ship in her harbor.”

Evie moved. It wasn’t a graceful movement. It was the lurch of a predator, unfamiliar with its own strength. She rolled Sophie onto her back. The redhead went willingly, her legs falling open to reveal the surreal anatomy. The three hard clits pulsed. The entrance waited, a slick, dark promise.

“You’re sure,” Evie grunted, not as a question, but as a final ceremony.

“Fuck me into the mattress,” Sophie begged, hooking her heels behind Evie’s back. “Break me open.”

Evie notched the broad, flaring head against that impossible opening. There was no tightness, no initial resistance. The flesh yielded as if made for it, a cool, wet silk that simply expanded. She pushed forward. Sophie’s body swallowed the mammoth crown with a soft, gulping sound.

“Oh, FUCK!” Sophie screamed, her back arching off the bed.

There was no stretch. Only profound, endless acceptance. Her internal walls were a velvet suction, mapping every ridge and vein of Evie’s shaft as it penetrated deeper, faster than should have been possible. Evie watched, mesmerized, as foot after foot of her own obscene length vanished into Sophie’s seemingly shallow body. It was optical insanity. It was heat and liquid and a clinging, perfect pressure that mounted with every inch.

Clare watched, one hand pinching her own nipple hard, the other buried between her own sore, leaking folds. She saw Evie’s hips meet Sophie’s, the entire monumental shaft fully sheathed. Sophie’s stomach distended slightly, a smooth, taut curve that outlined the shape of the intrusion.

“You’re all the way in,” Clare breathed, her voice husky with envy and arousal. “You’re fucking her in the womb, too. I can see it.”

Sophie was beyond words. Her eyes were rolled back, her mouth a silent ‘O’. Her three clits rubbed brutally against Evie’s pubic bone with every微小 thrust, a triple-point of blinding sensation. Her new nerves reported everything: the throb of the cock inside her, the scrape of a prominent vein, the hot pulse deep in her core where the tip now lodged.

Evie began to move. It was a slow, deep, sliding withdrawal followed by a relentless, bottoming drive. The sounds were obscenely wet, a squelching rhythm that filled the room. Each thrust pressed that outlined shape in Sophie’s belly deeper, rearranging her.

“Harder,” Sophie managed to rasp. “Don’t fuck me. Use me. I’m just a fucking sleeve.”

Evie snapped her hips forward, a brutal, piston-like motion. The bed shrieked. Sophie’s head knocked against the headboard. She wailed, a sound of pure, unadulterated ecstasy.

“Tell me what you are,” Evie growled, a newfound dominance surging through her, fueled by the absolute surrender beneath her.

“Your hole!” Sophie screamed. “I’m your wet, fucking hole!”

Clare came then, just from watching, just from hearing it, her body convulsing silently as she fingered her own tender, well-used flesh.

Evie’s pace became frantic, animalistic. She was fucking into a liquidity that threatened to consume her. The sensation was unlike Clare’s desperate, clinging tightness. This was a sublime, engulfing vacuum, perfectly shaped and infinitely deep. It pulled the orgasm from her like a plunder.

With a final, snarling thrust that made Sophie’s body jolt, Evie came. It was another torrent, another claiming flood jetting into a prepared, waiting depth. Sophie felt the hot spill, felt her own modified canal milk every drop, and her vision dissolved into a silent, white-hot static.

Evie collapsed forward, spent, her face buried in Sophie’s neck. The connection held, full and impossible.

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