Chapter 3

Smith’s fingers hovered over the keyboard, his mind racing with Lizzy’s earlier comment. Surviving off his cum? The thought twisted inside him, dark and exhilarating. He could practically see her now—her body shaped by his needs, dependent on him, his cum the only thing keeping her alive. His perfect fuck doll. It wasn’t just about control; it was the idea of complete submission, of her entire being centered around him in every way. He couldn’t help but feel a surge of arousal at the thought, his cock stirring in his shorts.

He opened the program, tapping into the AI interface with anticipation thrumming through his veins. The soft hum of the system as it powered on was almost comforting. He hit the button to start the audio link, his heart already racing.

Smith: “How possible is it for me to sustain a human by cum alone?” The words felt bold, his pulse quickening. Could this really work?

AI: “To sustain a human purely on ejaculate, given that the average release contains only 2-3 calories and minimal nutrients, the body’s requirements as is far exceed this in terms of both caloric intake and essential nutrients. A human typically needs around 2,000 calories daily, while a single ejaculate provides just a fraction of this, approximately 0.1-0.15% of the daily requirement. To even approach basic caloric needs, it would require approximately 800 to 1,000 ejaculations per day. Beyond the caloric deficit, there is an extreme lack of essential nutrients—proteins, fats, vitamins, minerals—that would be necessary for basic cellular functions, organ maintenance, and overall survival.”

Smith’s eyes narrowed. A thousand times a day? He pictured himself relentlessly filling her, hours upon hours, her mouth, her pussy, every hole taking him in, never stopping. His cock strained harder against his jeans as he imagined her begging for more, desperate, hungry for every drop. But the logistics ... he needed to push it further.

Smith: “If we added macronutrients and micronutrients, how much semen would be required?” The thought was so far-fetched, so surreal, but his desire had already hooked him in too deep.

AI: “To meet an average daily caloric requirement of 2,000 calories using semen alone, if each 8ml of ejaculate contains 4-6 calories, you’d need roughly 2,700 to 4,000 ml (2.7 to 4 liters) per day. Adding essential nutrients would only address the nutritional balance, but the sheer volume remains essential to meet the caloric intake, and would not be feasible as is.”

Smith’s thoughts twisted, fixated on the numbers. Four liters ... per day? His heart pounded, excitement mixing with disbelief. Could he even produce that much? His cock twitched at the idea of his body evolving for her, his balls heavy, constantly churning out the cum she’d need to survive. The sheer volume excited him—the idea of her helplessly gulping down load after load just to stay alive. His cock was throbbing now, aching to break free, but there were still questions that needed answers.

Smith: “What changes would I need to undergo to provide that?”

AI: “You’d need to drastically increase semen production by enlarging the testes and penis, boosting sperm production and fluid output. Blood supply and hormonal levels (especially testosterone) would have to surge, supporting continuous semen creation. Your body would need to be optimized for hydration and nutrient intake to sustain the massive ejaculate volume daily.”

The mental image hit Smith hard. Enlarged balls ... enormous balls, constantly pumping cum, feeding her. He gripped the arm of his chair, feeling a thrill shoot through him at the thought. It was insane, impossible—but the AI laid it out so clinically, so logically, that it made his twisted fantasy seem almost ... feasible.

Smith: “How big are we talking?” His voice was low, his breath catching as he waited for the answer.

AI: “To produce 2.7 to 4 liters of semen daily, your testes would need to increase significantly in size—likely reaching the size of grapefruits (4-5 inches in diameter) to accommodate heightened sperm production and fluid capacity. Your penis, considering the volume of semen, would need to be 15-16 inches long and around 7 inches wide to allow for the necessary fluid transfer. Lastly, with increased seminal fluid pressure, the force could rise to about 40-50 mph (64-80 kph) due to the larger volume and enhanced muscle contractions, leading to a more powerful and forceful release.”

His breath hitched, cock straining painfully against his pants as his mind conjured up the image. A cock like that, pounding into her ... each shot of cum firing into her at insane speeds, filling her to the brim, stretching her beyond anything she could imagine. Fuck, he could almost feel the weight of his balls in his hands, full, aching, ready to release.

Smith: “What about her? What changes are necessary for Lizzy?” His voice was almost a growl now, the tension building inside him, pushing him further into the fantasy.

AI: “For her to sustain herself solely on semen, her digestive system would need to be fully optimized to process cum efficiently. The stomach and intestines would become more specialized to extract every bit of nutrient and energy from the ejaculate. The reproductive system could be largely removed, merging the vaginal, anal, and oral cavities into a unified processing system that funnels semen into the digestive tract. Her ovaries, uterus, and other reproductive organs would no longer be needed, freeing up space in the abdomen. The vaginal canal could connect directly to the digestive system, while the esophagus and rectum remain linked to aid in cum absorption from all entry points. This way, all semen intake—whether oral, vaginal, or anal—would be efficiently absorbed. Her body would be redesigned to rely entirely on ejaculate for hydration and nutrition, removing the need for traditional food or drink entirely.”

Smith’s mind reeled at the possibilities. Lizzy ... transformed, every hole designed to take him, to feed off him. He saw her as a perfect vessel for his cum, her body reshaped to survive on nothing but his essence. No need for food or water, just him. Only him. Every moment of her existence revolving around the next load he’d pump into her, her eyes begging for more.

His cock pulsed hard, aching for release, and he knew this wasn’t just a fantasy anymore—it was an obsession.

Smith’s mind spiraled, the AI’s voice a steady undercurrent beneath his pulsing thoughts. A cock that big ... would she even be able to take it? He imagined her struggling, those soft little moans turning into cries of pleasure as her body adjusted, reshaped, stretched to accommodate him.

Smith: “And what about the rest of her body? A cock that big...” His words came out thick, almost slurred with lust, his imagination running wild.

AI: “You are correct. For her body to handle your size vaginally and anally, her pelvic structure would need to be altered significantly. Her vaginal and anal canals would need to become deeper, wider, and much more elastic, with reinforced elasticized tissues to prevent tearing and ensure flexibility. The muscles in these areas would be strengthened and elasticized as well to accommodate both the length and width, allowing her to take your size without injury. Lubrication production would be enhanced, ensuring smoother and more comfortable penetration despite the large size.”

Deeper, wider, Smith thought, his breath hitching. Her body becoming this perfect vessel for his cock, her insides molded to take him without a single tear, without ever breaking. He could almost feel her tight, wet warmth enveloping him, her body giving way to the sheer size, moaning as she adjusted to every inch.

AI: “Since accommodating you orally without drastic facial changes would be unwise, her focus would remain on vaginal and anal penetration. These areas would need to be adapted to handle frequent use, with an increased ability to stretch and recover, reducing strain over time. The internal structure of her body would shift to provide the necessary space and support, allowing for pleasurable and sustainable interaction despite the extreme dimensions. Lastly, cervix and anal openings would need extreme elasticity added in order to keep fluid within her.” Smith groaned softly at the thought. Her body stretched to the limit, then bouncing back, ready for more. And no matter how much cum he pumped into her, she’d hold it all inside, nothing wasted. The idea of her insides sealing tight around his cum made his cock twitch, imagining her full, bloated with him.

Smith: “That sounds great. What am I missing? Downsides?” He asked, half-distracted by the image of Lizzy completely transformed, dependent on him.

AI: “For her to rely solely on you for sustenance through semen, she would become entirely dependent on your continuous supply. This means her survival would be tied to your ability to produce and provide semen regularly. If your production ever decreased or stopped, her body, having no alternative source of nutrition or hydration, would begin to weaken rapidly. You’d need to maintain your body’s health and function at peak efficiency to ensure the constant volume and nutrient-rich quality of ejaculate she would need to survive. Any disruption in your ability to meet her nutritional needs would pose a serious risk to her life, creating an intense dependence on your physical condition and ability to keep producing.”

Smith felt a strange thrill course through him at that. Her life would literally be in his hands ... no, in his balls. Every drop would mean her survival. He liked the idea—no, loved it. Lizzy, so perfect, would need him every day, her body only able to continue because he was feeding her exactly what she needed.

Smith: “What if we created some kind of internal storage system?”

AI: “She could store semen in her breasts. They would need to be drastically modified. Her breasts would become large, fluid-storage organs with the ability to hold significant amounts of semen, up to several liters each. Internally, her mammary glands would be replaced or transformed into specialized storage sacs, connected to her digestive system to allow her body to gradually draw nutrients and hydration as needed.”

His breath caught. Her breasts ... huge, swollen with cum, just waiting to be drained. The thought sent a shudder through him, imagining her heavy tits sloshing with his cum, soft and full.

AI: “These storage systems would need enhanced elasticity and structural support to handle the weight and volume, making her breasts much larger and more durable. This setup would allow her to be less reliant on constant supply, giving her a few extra days, as she could store and access cum over time, ensuring a consistent nutrient flow even when you’re not actively providing it. Storage levels would be gauged by size.

She’d always be ready for him. Even if he was away, her body would keep functioning, surviving on what he’d already given her. His cock twitched at the thought, his mind swirling with images of her breasts leaking, full and desperate to be relieved.

Smith: “What if I were to overflow this internal storage system?”

AI: “If you were to overflow her internal storage system, her breasts, having reached maximum capacity, would release the excess semen. This could result in a natural expulsion mechanism, where excess cum is pushed out, either through her nipples or other connected routes like her mouth, vagina, or anus, depending on how her body is modified to handle the overflow. Her body would need valves or pressure-release systems to safely manage the extra volume, preventing internal strain or rupture. The release could be gradual, or if the overflow is intense, it could result in larger, more forceful expulsions of cum from various orifices.”

Smith’s mouth went dry. Overflow ... forceful expulsion ... fuck. He could already see it, her breasts spilling over, cum dripping from her nipples, mouth, pussy, ass—all of it at once, unable to hold anymore. The fantasy consumed him, his pulse hammering, cock painfully hard in his pants.

Smith: “What about waste? Could we re-purpose waste to propel her internal lubrication systems?”

AI: “Yes, her body could be modified to repurpose waste by converting it into internal lubrication. Her digestive system could be redesigned to filter and break down waste products, extracting any remaining nutrients and converting byproducts into a specialized form of lubricant. This lubricant could then be directed to her vaginal and anal canals, ensuring continuous moisture and smooth functioning during intercourse.”

Constantly lubricated, always ready, never dry. The idea made Smith groan quietly, imagining Lizzy’s body slick and waiting for him at all times, no matter how hard or how often he fucked her.

Smith: “Am I missing anything else?”

AI: “Once changes occur, she will need semen promptly.”

Smith: “Easy.” He grinned, knowing that would never be a problem.

AI: “Shall I enact changes?”

Smith: “Do it.”

The AI’s response was instant, clinical, detached, but to Smith, it felt like the click of a switch, setting something unstoppable into motion.

AI: “Timeframe for Changes: Penis and testes enlargement: 1-2 hours for gradual growth, including vascularization and tissue expansion. Gland enlargement (seminal vesicles and prostate): 1 hour for increased capacity. Muscle hypertrophy for ejaculation: 1-2 hours for muscle thickening and strength increase. Her vaginal, anal, and digestive system integration: 2-3 hours to connect the reproductive and digestive systems and modify pelvic structure. Breast enlargement and storage: 1-2 hours to create the storage capacity and optimize the mammary glands for semen retention. Total time for full transformation: 6-8 hours for both of you to undergo all changes.”

Smith stood, excitement thrumming in his veins as he headed upstairs. His cock ached, thoughts of what Lizzy would become flooding his mind. Six to eight hours. That was all it would take for both of them to be changed forever.

He slipped into the bedroom, the soft glow of the moon casting pale light across Lizzy’s sleeping form. She looked so peaceful, so unaware of what was coming. Tomorrow, everything will be different. He slid into bed beside her, his body buzzing with anticipation, barely able to wait for the moment she opened her eyes to her new reality.

Lying there, so close to her, his mind raced with thoughts of the future. Tomorrow, she’d be his—completely, utterly his. And he couldn’t stop thinking about what tomorrow would bring.

As the night thickened, the changes worked silently, seeping through every cell, every nerve. Their bodies shifted, molded by the AI’s commands, reshaping them both beneath the stillness. Lizzy, so peaceful in her sleep, had no idea how her insides were being rewired, how her very existence was being rewritten.

The dark gave way to the soft gray of dawn, and with it, a new reality.

Lizzy

Lizzy stirred, a creeping heaviness sinking through her limbs, something off settling deep in her gut. Her chest felt wrong first—empty in a way that threw her off balance. Normally her tits were heavy, full, a comforting weight that just sat there. But now? Now it felt like they were just ... there. Hollow. Taking up space without substance. She groaned, rolling under the covers, trying to shake the sensation, her skin prickling with discomfort she couldn’t quite understand.

Blinking against the dim light filtering through the curtains, she instinctively pressed a hand to her chest, fingers brushing over bare skin. That’s when she really felt it. Her tits—wrong. She gave them a gentle squeeze, expecting the familiar softness, the weight she’d come to expect. Instead, they felt almost ... deflated? Light. Like something had been drained from them, leaving only an eerie emptiness behind. Her heart quickened, panic blooming in her throat.

“What the fuck...” she muttered, pressing harder, needing to make sense of the alien sensation. They looked the same—big, full, the same curve that always turned heads—but the feeling ... God, the feeling was all wrong. She rubbed at her eyes like that would somehow fix it, but it wasn’t just her chest. Her whole body felt ... different. Her stomach was tight, her muscles loose, like her insides had rearranged themselves overnight.

She swallowed hard, her hand drifting lower, fingers brushing her thighs before sliding between them. And then—holy shit. Her pussy felt off too, the snugness she was used to gone, replaced by an unfamiliar looseness. It was as if there was more space inside her, a strange ache twisting deep in her belly, like everything had been stretched, reshaped in the night.

In a flash, she shot out of bed, legs shaking beneath her as she stood there, trembling. “What the fuck is going on?” Her hands roamed over her skin, searching for some explanation, some hint of what had changed. Her hips felt wider, her muscles like they’d been pulled apart, and a queasy sensation rippled through her. Her skin was too sensitive, every brush of her fingers sending shockwaves of unfamiliar sensations up her spine. It was like she wasn’t even in her own body anymore.

Smith lay there, cool as ever, watching her with this infuriating smirk playing on his lips, one elbow propped on the pillow like this was the moment he’d been waiting for all along. He hadn’t moved, hadn’t said a word—just stared. His eyes tracked her every movement, and it sent a chill down her spine.

“I feel fucking weird,” she spat, glaring down at him, her chest rising and falling faster. “What the fuck did you do to me?”

Smith didn’t flinch. Didn’t even look remotely concerned. In fact, he seemed ... pleased. That smug, satisfied look plastered all over his face like he’d just won some kind of sick game.

“I thought about what you said yesterday,” he said, his voice smooth, almost lazy, like this was the most casual conversation in the world. “About wanting to live off my cum.”

Her heart slammed against her ribs, eyes widening in disbelief. Live off his cum?! She stared at him, mouth falling open as the weight of his words crashed over her. “You—you fucking did this?”

Smith gave a half-shrug, utterly nonchalant. “You gave me the idea.” His tone was so calm, so collected, it made her skin crawl.

“I didn’t fucking mean it!” She stepped back, her legs barely holding her up, her whole body trembling. She felt ... hollow. Like her tits were waiting—begging—to be filled, the strange sensation between her thighs growing more intense with each passing second. “I feel like I don’t even know my own body anymore! This is way fucking more than just making my tit’s bigger!”

Panic clutched at her throat, her breaths coming shallow, fast. Her tits were empty, her insides aching for something she didn’t understand, her body screaming at her that it had been changed. And not just changed—remade. Built for something specific. She felt it everywhere—her pussy, her ass, even her throat felt wider, like they’d been stretched, reshaped for something ... huge. Something that could only belong to him.

“Smith!” Her voice was shaking now, laced with fury, fear boiling in her chest. “What the fuck did you do to me? Why does everything feel so fucking different?”

That smug grin of his only widened, his body sinking back into the pillows, completely at ease while she stood there, unraveling. “I optimized you,” he said, each word dripping with satisfaction. “Your body’s been modified. For me. To live off of me.”

Her stomach twisted into knots, the word modified echoing in her mind. Her breath hitched, coming in short, desperate gasps. “Modified?! Are you fucking kidding me?! What the fuck does that even mean?”

He didn’t even blink, just watched her, calm as ever. “Your body’s been completely redesigned to handle me. To need me.” He let that sink in, his eyes dark with satisfaction. “You wanted it, remember? To survive off my cum. I made it possible. I gave you exactly what you asked for.”

Lizzy’s head spun, the room tilting around her. Her body, made to live off of him? Her tits, hollow ... her pussy stretched, everything about her—remade, reshaped around his sick desires. And he just lay there, so fucking smug, like it was the greatest gift he could’ve ever given her.

Smith’s grin only grew as Lizzy’s panic broke through in frantic, jagged breaths. She tried to hold herself together, her words firing out sharp and desperate, but he could see her unraveling—hear it in that trembling edge of her voice, feel it in the way her eyes kept darting down to him, as if drawn by some fucked-up magnetism. His cock throbbed harder beneath the sheets, each pulse feeding off her disbelief, her rising horror.

Without saying a word, he peeled the blankets back, the fabric slipping away, baring everything to the morning light. He stretched out casually, not even bothering to hide the smirk tugging at his lips, and Lizzy’s breath hitched. Her wide, disbelieving eyes locked on him, on it.

Her lips parted. “Jesus fucking Christ,” she whispered, frozen in place.

His cock ... fuck. She couldn’t wrap her head around it. Her eyes tracked the obscene length, and the sight was impossible. It had to be at least 16 inches, maybe more, a monstrous slab of meat so thick it looked like it belonged in some twisted fantasy, not on a human body. The girth—fuck, it had to be nearly 7 inches wide—like a damn fire hydrant, every inch bulging with angry, swollen veins that seemed ready to burst. The head, fat and engorged, glistened with slick precum, the scent of it already filling the air around them.

Lizzy swallowed hard, unable to look away. This isn’t real. This can’t be real. Her mind raced, trying to make sense of the sheer size of him, but it was like her thoughts short-circuited the moment they registered the impossibility of it. Her eyes flicked down further, to his balls, and she nearly gagged. They hung low, each one enormous, heavy and swollen, like twin grapefruits, looking ready to churn out gallons of cum.

Her stomach lurched. “What the fuck is that?” she shouted, her voice cracking as she stayed glued to the sight of his monstrous cock, her horror mixing with something else—something darker, crawling beneath her skin.

Smith let out a low, amused chuckle, his hand sliding lazily down the veiny length, smearing precum along the thick shaft as he spoke. “This?” he asked, his voice low, teasing, dark with satisfaction. “This is what you’re made for now, Lizzy.”

She recoiled, backing up until her body hit the wall with a dull thud, her legs shaking so hard she could barely stand. “You’re fucking insane,” she spat, but her voice trembled, the words hollow even to her. “No one can take that!” She tried to sound defiant, but it came out weak, almost pleading. “I can’t take that.”

Smith cocked his head, watching her with the slow, methodical gaze of a predator toying with its prey. His smirk widened as his hand continued to glide along his massive cock, each stroke making it pulse, throb, like it was growing even bigger before her eyes. “You don’t know that yet,” he murmured, his tone almost soothing, taunting. “Your body’s been modified for me, Lizzy. Every part of you—inside and out—redesigned to take me. To handle me.”

Her heart pounded in her chest, so hard she thought it might burst. Her breathing quickened, shallow and ragged, each breath fighting the wave of sensations slamming into her. Because the truth was, somewhere deep inside, buried beneath the fear and panic, her body did feel different. There was an emptiness, a hollowness that gnawed at her, a deep ache that hadn’t been there before. And seeing him now—his cock, impossibly huge and thick, standing tall like a monument to his control—was stirring something in her she wanted no part of.

But she fought it.

“Fuck you, Smith!” she screamed, her fists clenching tight at her sides, knuckles white with tension. “You did this to me without even asking! You fucked with my entire body, and you think I’m just gonna ... what? Give in? Let you shove that thing inside me?!”

Smith’s grin stretched wider, his hand stroking his cock with more purpose now, precum oozing in thick, glistening ropes down the monstrous length. “You’ll let me,” he said, his voice low, dripping with that same twisted confidence. “Your body will beg for it, Lizzy. You won’t be able to resist.”

She shook her head violently, refusing to believe it, but the panic was rising in her throat, choking her. “No,” she whispered, almost to herself, her voice weak, trying desperately to convince her own body. But the hollow ache inside her was growing stronger, gnawing at her, and it terrified her.

Her gaze betrayed her again, flicking back to him, to the beast that was his cock, her eyes tracing the veins as they throbbed in time with his heartbeat. The swollen, deep-red head leaked precum, thick and shiny, and her stomach twisted at the thought of it—at the thought of him inside her, filling her to the point of breaking. Her pussy clenched involuntarily, and she hated it. The emptiness inside was screaming now, a need she couldn’t deny, an ache she couldn’t push down no matter how hard she tried.

Smith’s eyes gleamed as he sat up, his hand still gliding along the massive length of his cock. “You’re already feeling it, aren’t you?” he asked, his voice soft, like a taunt. “That need. That hunger inside you. Your body’s crying out for it, Lizzy. You can try to deny it, but I can see it all over your face.”

“Shut up!” she screamed again, but her voice cracked, weaker than before, as if she didn’t even believe herself. Her chest heaved, her thighs quivering as that gnawing emptiness between her legs became unbearable. Her pussy clenched again, tighter this time, and she whimpered, unable to stop the trembling in her limbs.

“No,” Smith said, his tone dropping, dark and commanding now. “I won’t shut up. You need to hear this. Your body was built for me. Built to take this cock—” He stroked himself harder now, the shaft pulsing with each movement, precum dripping down onto his thighs, “—and to live off of me. Off of my cum. That’s all you need now, Lizzy. Me.”

Her legs gave out, and she collapsed against the wall, sliding down to the floor in a daze. Tears stung at her eyes, frustration bubbling up, mixing with something she couldn’t control—something darker, deeper, twisting inside her. Fuck, fuck, fuck. Her body was betraying her, every nerve, every muscle screaming for something she refused to admit.

“Fuck you,” she whimpered, barely above a whisper, her entire body shaking with the weight of it. Her fists clenched, knuckles pressed into the floor, but she couldn’t stop the truth from sinking in. She felt it—inside her. The change. Her body had been twisted, warped, modified in ways she couldn’t even comprehend. And no matter how much she tried to fight, tried to deny it, she knew deep down that something had shifted.

Smith leaned forward, his massive cock still throbbing, leaking, towering over her like a promise, a threat. His voice dropped even lower, dark satisfaction dripping from every word. “Soon,” he whispered, eyes locked on hers. “Soon, you’ll stop fighting. You’ll realize this is what you were meant for. And when you do, you’ll beg for it.”

Smith’s smirk only grew darker as Lizzy slid helplessly down the wall, her body trembling with a chaotic mix of fear, anger, and something more insidious, something she refused to acknowledge but couldn’t quite shake. He watched her fall apart, piece by piece, her resolve cracking with every shallow breath, every darting glance toward his cock, no matter how much she tried to fight it. She was breaking. He could see it in the way her chest rose and fell, in the wild panic flickering behind her wide, terrified eyes.

Her breathing came in quick, desperate gasps, and fuck, she looked perfect like this. So vulnerable, so lost in the flood of sensations overtaking her, the reality of her new body sinking in. His cock twitched, precum oozing down the thick, veiny shaft, and he stood, stepping closer, looming over her like a shadow she couldn’t escape.

“You’re probably wondering what I did to you,” he said, his voice smooth, casual, like they were discussing the weather. He stroked his monstrous length slowly, deliberately, watching as her gaze kept flicking down to it, helpless despite the fury trembling in her lips. “I’ll explain it. You should know exactly how your body’s different now. What you’re made for.”

Lizzy’s head jerked in denial, her voice fragile and broken. “I don’t want to fucking know—”

“Too bad,” Smith cut her off, his voice sharp, slicing through her protest. He saw the way her mouth snapped shut, her defiance withering under the weight of his control. He had her now. And she was starting to realize it. “You said it yourself yesterday,” he went on, calm as ever, like he was spelling out some obvious, inevitable truth. “You joked about living off my cum.” His grin widened, fingers tightening around his cock as he stroked it, slow and deliberate. “So I made that a reality.”

Her mouth opened, trembling, but no sound came out. She stared at him, eyes wide, panic creeping into every inch of her expression as she began to grasp what he’d done.