Jessica's Guinea Pig

by MatthewVett

Caution: This Erotic Sex Story contains strong sexual content, including Ma/Fa, NonConsensual, Reluctant, Heterosexual, Science Fiction, Humiliation, Oral Sex, Exhibitionism, Sci-fi sex story.

Desc: Erotic Sex Story: He volunteers for an experiment, but he doesn't realize just what he's getting into. Suddenly, his cock is under her control!

"Volunteers needed for a scientific study. Easily earn $500. Must be a healthy, adult male," read the poster, stapled crudely to the bulletin board in the sub-basement of the biotechnology building. None of the number slips had been taken yet. Good news, I thought to myself. I tore off every slip, pocketed one of them, and threw out the rest. They'll have other chances.

Maybe I was stalling scientific progress, but as a broke grad student, I had no guilt about making money, nor shame about how I made it. I did studies, I volunteered to be an art model, I even had a small, steady stream of income from giving stressed out undergrad girls massages. But $500 was a nice haul, if it were legitimate. And the less competition I had, the better my chances. I looked around the deserted basement. Two vending machines haunted one wall, silently humming away, their banners advertising drinks and snacks that had stopped being produced when I was in diapers. About half the lights were broken, as were half the chairs. A few dusty tables were scattered about the floor, and down the hallways that radiated outwards from either side were the offices of the unluckiest TAs on campus, who tended to hold their office hours in cafes or at the library, anywhere besides here. I came for the privacy almost every day. I took the crumpled up slip out of my pocket and examined it while I packed my stuff up, ready to head home. Five hundred dollars, I said, grinning inwardly, here I come. It seemed almost too good to be true.

"Thank you so much for coming!" bubbled the lab assistant who greeted me at the door. "My name is Jessica, and you must be Matthew, right? You know," she mused with an adorable pout, showing off a small, silver lip ring, "no one else even applied! Anyways, are you ready for the experiment?" I nodded and she gestured towards a door in the lab. "Everything's set up right in there. Let's get started!" she said, rubbing her hands together in anticipatory glee. Bit of a strange girl, I thought to myself, but money's money. I wondered what I'd have to do as I followed her swaying behind through the door.

The room was brightly lit with white walls. It looked so sterile, almost like the rooms where they construct microchips. Only one wall wasn't white, but instead a mirror. Probably one-way glass, I reflected. Facing it was a large, comfortable black chair that had a metal box on the back. "Please, sit down," said Jessica. "I'll get you ready for the experiment." I obeyed and sat down in the chair. Jessica walked towards me and I let my eyes linger over her luscious body as she approached.

She was pleasantly zaftig, her curves filling out her clothes nicely. She was wearing a white lab coat that nearly reached the ground. It had a deep neckline, revealing nothing beneath I could see. I tried to stretch my neck a bit to stare down it, but I could only see a deep cleavage and the tops of her enormous, tanned breasts. They had to be at least DDs ... As she bent down to fix some straps over my wrists, I was too entranced by her heaving chest just a few inches from my face to be worried about her actions. I was certain they would spill out into my waiting face if she had the slightest jostle. But all too soon, she stood back up, and I realized that my arms were restrained.

"What is this for?" I asked her.

She smiled. "Don't worry, you'll enjoy it. I just want to make sure you can't..." she paused, looking for the right word while I felt her eyes travel down from my face to the lap of my pants, already bulging from before, "I want to make sure you can't end the experiment too soon." She got down on her knees in front of me, giving me another eyeful of her delicious, massive chest and began to attach some monitors to my arms. She undid the buttons of my shirt and attached another one of my chest. Two more went onto my forehead, and another on the back of my neck.

Next her fingers danced down my stomach to the fly of my jeans and began to slowly unzip me. My eyes widened. "What sort of experiment is this?" I finally asked her.

She looked up at me with big, dark brown eyes, her fingers still deftly worked while she spoke. Her sleek, long, black hair flowed down her shoulders, and a stray bang covered her left eye. Her cheeks were full and a healthy pink. Her adorable lips framed a perfectly white smile. "I'm going to study your reaction to some videos," she explained as she reached into my boxers and pulled out my throbbing cock. I was speechless, but she just grinned and giggled at the sight of my hardness. "Oh my, you're easily excited, aren't you? Don't go off yet, big boy. You're just perfect, exactly what I need. Although ... I can't start until you're soft." She absent-mindedly stroked my shaft up and down. "Do you think you can get it down on your own?" she asked.

I swallowed deeply. "No. I think I need some help," I pleaded, hoping I was right about where this was going.

"Well, if you insist," she breathed huskily. My hips bucked in anticipation slightly, my cock desperate for the friction of her hand against me. She reached into one of her labcoat pockets and removed a small tube. Lubrication? She squeezed some into her hand and wrapped it around my shaft.

Oh Jesus... "Don't worry, it's supposed to feel that cold," she methodically explained. "The temperature should induce some shrinkage, and once you're down to size, we can start the experiment." She smiled while she watched me squirm, my dick shriveling from the cold. She put a hand over her mouth and stifled her laughter. "Ohhh, it's so cute when it's that small!" I blushed and gritted my teeth, turned my head to avoid her eye contact. Oh you just wait, I fumed, as soon as I'm out of this chair, I'll show you how big it gets!

I looked down at my wilted penis while Jessica affixed some wired bands to it, smiling pleasantly. She stood up and checked the wires' connections to a small cabinet on the back of the chair.

"The computers will monitor you from the control room, Matthew," said Jessica, walking over to me and getting down to her knees. "Just relax," she cooed, taking my flaccid cock into her warm mouth. "I'll handle everything." She closed her lips and began to softly suckle my dick as I felt it begin to grow instantly inside her. Her eyes closed in delight and she moaned softly. I leaned back in my chair, savoring the sensations.

She brought her lips to the very tip of my cock and began to gently kiss the large, swollen head and the top of my shaft, while her hand was stroking my shaft. She caressed her blushing cheeks with my manhood, gasping in ecstasy. She cupped my balls in one hand, massaging them delicately, while she returned my shaft to her lips. Her tongue swirled around me, she bobbed her head up and down, she sucked and licked my long, thick cock.

Suddenly Jessica released me from her mouth and began slowly sliding her hand up and down the length of my shaft. "Sorry Matthew," she apologized, "but if you finish too soon. I won't get the data I need. Do you think you can last much longer?"

I shook my head back and forth. "God no," I confessed. I had been a few seconds away when she had cruelly stopped. I was worried I was going to burst in her hands onto her face while she spoke. I was so close I could feel it.

She tsked playfully. "What am I going to do with you?" she asked. She unbuttoned her labcoat and pushed it open. I had been right before: she was topless under it. Her enormous breasts brazenly jutted outward. She leaned forward, resting her massive chest on my lap, while she positioned by cock inside her cleavage. "Well, this ought to keep you hard without seeing you off," she thought aloud. God, what sort of tease was this girl? Such torture! Her breasts were so soft, so warm. I wanted to bury myself in her cleavage. Her cocoa brown nipples were pebble hard, and while she waited, she slowly swirled one finger around her nipples while she bit her lower lip, staring into my hungry eyes the entire time.

"You poor thing," she monologue. "You're really earning that money, aren't you? This must be such torture for you. I bet you're just begging to orgasm. I bet the thought of waiting even a minute longer is just unbearable..." She began to press her tits together, massaging my cock between them. "Oh! The look on your face ... I almost set you off then, didn't I?" She giggled at my predicament. "Boys are just so cute. I love playing with a hard cock. The way it pulsates, mmmm ... I could just sit here with your cock between my tits all day." She leaned her head down and lightly kissed the tip of my shaft; once, twice, covering it with loving affection.

"Well, that should be enough data. Are you ready to finish, Matthew?" she asked.

I weakly nodded. Oh god yes! Jessica got down onto her knees and looked deeply into my eyes before beginning anew. She impaled herself upon my painfully hard cock, fucking me with her mouth, bobbing her head up and down rapidly. Her eyes never broke away from mine. Her loud slurps seemed to echo across the room. Her cheeks sunk in and filled out in succession as she sucked the shaft. I felt myself cross the point of no return and felt a combination of excitement, relief, embarrassment, and fear. I dug my fingernails into her shoulders. I cried out loudly, wordlessly, an animalistic utterance. Powerful waves of pleasure coursed through my whole body as I orgasmed, emptying myself into her. Her eyes widened in surprise as the first spurt of cum gushed into her mouth, but she simply flared her nostrils and began sucking down my semen. She mmmmed as my cock pulsated inside her. Seven, eight, nine loads of cum burst forcefully out of me before the pressure began to ease. My jaw was slack. I breathed in and out with staccato breaths.

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