Chapter 1: Introduction
The flyer was half-buried on the campus bulletin board, stuck under a curling ad for “Yoga for Stress Relief.”
VOLUNTEERS NEEDED — CUTTING-EDGE BIOMEDICAL RESEARCH
Generous compensation. No experience required.
I’d been on the university’s research participant list for a year or so. Easy money for a broke grad student. Most of the time it was boring stuff–memory games in basement labs, treadmill runs with heart monitors, a needle in the arm now and then. Nothing major.
This one was different. It paid triple.
Two days later, I was in a small exam room. White walls. Vent humming overhead. A tablet in my hands, spitting out survey questions while some smoking hot assistant wrapped a cuff around my arm.
At first, it was the usual sleep and diet crap. Then the questions got personal. Sexual history, number of partners, how often, what I liked, whether I’d tried anything “unusual.” Fifty of them in a row, no exaggeration. I slowed down, wondering if I should ask, but the assistant didn’t even look up from their laptop.
After a few questions about oral sex, I looked at the assistant. She was exactly my type. Perfect body, long brown curly hair. I cleared my throat and asked, “I forgot your name. Could I get some water?”
She smiled and blushed, but still remained focused on her laptop. A speaker in the room said, “Please do not speak with the assistant. Please finish the questions. Water is available after this part of the vetting.”
When the survey ended, the assistant walked me down to the professor’s office. Whole different vibe the second I stepped inside. The hallway outside was bright and cheap. In here, the light was softer, the furniture heavier, the walls lined with journals and framed patents.
The professor stood as I walked in. Tall. Sharp features. Eyes that landed on me and stayed there, like they were reading more than just my face.
“Mr. Carter,” they said, motioning to the chair across from the desk. “Thank you for coming. I’ll be direct. Our team has developed a method to safely and reversibly change a subject’s biological sex. Not cosmetically. Fully. Anatomically, hormonally, genetically. Indistinguishable from someone born that way.”
I blinked. “You mean actually…”
“Yes. Total change. Hundreds of animal trials, zero complications. You’d be the first human.”
A laugh slipped out of me. “Yeah, no thanks.”
The professor didn’t react. “You’d be the only living person to know both sides. Not in theory. Not in fantasy. In reality. To know how each body feels. Including the difference most people only imagine.” Their voice dipped slightly. “You’d be the first to experience orgasm from both perspectives. Haven’t you ever wondered?”
I didn’t answer. Not then. But the question stuck with me, and it didn’t go away. The professor continued to explain the process, but I was lost in thought.
“Yes,” I blurted out. “I have wondered. Who hasn’t? I guess what I’m saying is, I’m in.”
“Of course Mr. Carter,” the professor said, smiling, “I assumed you would be.”
I signed all the papers.
Chapter 2: The Transformation
The lab felt colder in mood than in temperature. Gray walls, no windows, nothing left out. In the middle stood a tall, very modern-looking medical chair with metal arms hanging over it, like a dentist’s chair redesigned by an engineer who hated comfort.
Two assistants worked in silence, attaching electrodes across my chest, thighs, and calves. One of them was the girl I had seen before. She was just as beautiful as I remembered, but all my attempts to catch her eye seemed to fail. Then came the headgear. Not one cap, but dozens of small leads pressed into my scalp, temples, even along my jaw. Each one glowed faintly, blinking in slow patterns.
The chair padding looked soft, but wasn’t. Straps tightened around my wrists, forearms, and ankles. I shifted against them, testing, and that was when the professor spoke behind me.
“The process is painless. Three minutes, start to finish. You will not be conscious during the restructuring.”
I opened my mouth to argue, or maybe just stall, but the IV was already in my arm. The sedative hit fast. My tongue went heavy, the lights above me blurred into halos.
The professor’s voice followed me into the dark.
“You will wake in a body no one else has ever known from the inside.”
I surfaced slowly, like swimming through syrup. The overhead lights were the same, but the hum had changed. Or maybe my ears had. My mouth tasted metallic.
Something was off. My hips pressed wider into the chair. My elbows rested at a new angle. Even the blanket brushing against me felt heavier, strange.
I pushed myself upright. Hair slid forward over my shoulders, brushing my upper arms. Long hair. My breath caught.
My hands were narrower, fingers slimmer. When I flexed, the tendons shifted in ways that felt wrong, like they belonged to somebody else.
Looking down, I saw smooth legs. Smaller knees. Narrow feet. Ankles that bent differently when they touched the floor.
“Steady,” the professor said from behind me. Calm, patient. “Your equilibrium will return.”
The restraints loosened and vanished as quickly as they appeared.
I turned toward the voice and froze.
Across the room stood a mirror.
The reflection wasn’t mine. The eyes, maybe, but the jaw was softer, cheekbones higher, hair spilling in uneven waves across bare shoulders. The gown tied behind me hinted at curves that made my pulse spike.
My hand went to the tie without thinking. The knot slipped, and the gown slid forward, catching at my elbows.
The body beneath was undeniable.
My hand rose, brushing lightly against a breast.
“Please don’t,” the professor said, tone level but absolute. “Section Twelve, Subpart A: no self-pleasure during testing.”
I dropped my hand.
The professor stepped into view with a clipboard. “We will begin with baseline mobility tests. Then you will see just how extensive the transformation is.”
Chapter 3: The Tests
The professor stood a few steps away, eyes on a tablet.
“The transformation appears complete. Congratulations. You are the first. From this point forward, you will be referred to as Subject X-1.”
They tapped the screen and kept talking. “We will begin baseline assessments.”
The next forty minutes went by in a blur of instructions.
First came stretches. My favorite lab assistant, now wearing pale gloves, guided me through them. Arms overhead, fingers to the floor, twists at the waist, knees pulled tight to my chest. Everything felt slightly wrong. Different muscles pulled. Smaller joints tightened sooner. My hips moved with a strange looseness. The assistant mostly watched the monitors, but a few times I caught her looking straight at me before writing notes.
Then came the breathing test. A mask sealed over my mouth and nose. I inhaled on cue, cool air flowing in, the amplified sound of my exhale filling the room. My lungs felt smaller, the rhythm faster, every breath pushing differently against my ribs.
Grip strength followed. The professor handed me a device shaped like a handle. “Squeeze until you hear the tone.”
The tone chirped too soon. My new muscles gave out long before my old baseline. The professor recorded the number without comment.
Other tests were stranger. A probe against the back of my neck sent a faint buzz through my nerves. Reflex sensors tracked my twitching legs. A balance board mapped the tiny shifts in my stance. Every step reminded me that this body was new ground.
When the last number was logged, the professor turned to a fresh section on their tablet.
“Only a few tests remain,” they said. “Giving oral. Receiving anal. Receiving oral. And finally, intercourse.”
I stared at them. “What?”
“It was in the forms you signed. Section Fourteen, Subsection C. Assessment of sexual function and adaptation under gendered stimulation. You were a heterosexual male. Now you are female. We need to know if the new hormones override the old feelings.”
He spoke as he wrote on his tablet, “Subject’s testosterone seems to be lingering longer than expected.”
He continued, “Your hesitation is expected, but our projections suggest enthusiasm will rise as your hormones adjust once the procedure begins. The electrodes on your head are not for show. We will know exactly how you feel at every moment. This research matters.”
I shook my head. “No. I’m not doing that.”
The professor did not flinch. “I am sorry to hear that. We will reverse the process immediately. You will still receive the minimum payout.”
They turned toward the equipment.
“Wait,” I said.
The professor paused.
“If I stop now, that’s it?”
“You will be the first transition, but not the first to have lived to experience both the male and female orgasm. But when the procedure becomes public — if you can afford it — you will still have the chance. If you remain here and complete all of the testing, there will be significant interest in your account. That is one reason there is no nondisclosure. Publishers will pay well for your story.”
I swallowed. “What exactly is left?”
“For oral, there will be two subjects. One below average size, one above. After the first, we expect you will want the second, especially once you see him. Then you will have a two-hour break. You may eat, rest, or do as you wish, except for self-pleasure. After the break, you will choose which of the two will participate in the anal evaluation. Following that, you will again choose which subject will participate in the receiving oral. And finally, you can again choose which subject for intercourse. However, we do need to know.. are you in or out?”
I almost laughed at the wording. “If I say yes, can I still stop whenever I want?”
“At any moment,” the professor said without hesitation. “No one will force you. But once you stop, the evaluation ends and your payout is reduced. This was all laid out in the documents you signed.”
I exhaled. “Fine. I’ll do it. But don’t think I’m looking forward to this.”
“Of course you aren’t,” the professor said, eyes back on the tablet. I wasn’t sure, but I think I detected a small smirk on his face.
Chapter 4: B-17
The professor checked the clipboard. “This is Subject B-17. Length: four point six five inches, slightly below the mean. You will begin with him.”
The door opened. A man walked in, nude, posture relaxed, but he seemed a bit nervous. Behind him, the female attendant wheeled in a cart of monitoring equipment. Wires trailed neatly to electrodes on his temples, chest, and thighs. The machine hummed steadily.
“That is our biometric station,” the professor said. “It records his heart rate, respiration, muscle activity, and neural response. Your readings will be synchronized for comparison.”
B-17 met my eyes and immediately looked away shyly. He hardened quickly, no words, no hesitation.
I glanced at the attendant. She was gorgeous, her lab coat hinting at curves beneath, but I found my gaze drifting back to him.
“As expected,” the professor said, still looking at the screen, “hormonal activity is overriding obsolete impulses.”
The attendant placed a padded platform in front of my chair. “This will bring the subject to the correct height for you to remain seated.”
B-17 stepped up, close now.
“I don’t know how to do this,” I muttered.
The professor flipped pages. “According to your history, you received fellatio forty-eight times from six partners. That should make you passable at giving it. Proceed.”
B-17 did not move. My body leaned forward anyway, lips hovering inches from him. Heat radiated from his skin, carrying a mix of soap and musk.
I closed my lips around him. The shock was in the texture: soft skin over hard muscle, the head warmer still, pulsing faintly. I started slow, tongue adjusting, saliva building. The taste was sharp, saline, undeniably alive.
His breathing shifted. My hands braced on the chair as I found a rhythm. The ridge beneath the head, the taut skin, the faint flex of muscle beneath — I cataloged every detail.
He never looked away. His eyes stayed on mine, steady, unreadable, and that stare made every twitch in his thighs feel sharper.
The pulses came faster. His legs tensed, hips held back by control. Then a sudden hard throb, and heat filled my mouth in waves. Metallic, salty, thick. Reflex made me swallow, dragging him deeper for the last few surges.
When I pulled back, cool air hit my lips. The female attendant pressed a cold compress to my jaw.
Subject B-17 left the room.
“The next subject measures six point two five inches,” she said in a neutral tone.
Chapter 5: S-3
The door opened again. Subject S-3 entered. Lean build, more definition, presence that filled the space. Fuller in girth, already swelling as he walked toward me.
“Subject S-3,” the professor said, making a note. “Slightly above mean. The evaluation will..”
“Let’s just do this,” I cut in.
The difference hit me right away. My lips stretched wider, my jaw working harder. His weight pressed heavier on my tongue, filling me almost completely. I let my tongue explore more this time, tracing lines, listening for the change in his breathing.
Going deeper was harder. The flare of his girth pushed at my throat, but I managed. His taste was cleaner, almost sweet, compared to the first. I felt myself wanting to impress him.
His breathing grew rougher. My jaw ached, but I kept moving, adjusting, finding a rhythm. The pulses came stronger than B-17’s, his body shuddering with each one. Heat spilled into my mouth in heavy waves. I swallowed again and again until the last tremor eased.
I let him slip free. My lips tingled, jaw sore.
He lingered a moment, chest rising and falling. Then, almost without meaning to, he smiled. Not smug. Just satisfied.
Then he stepped back, and the female attendant was there with a cold compress to soothe my aching jaw.
Chapter 6: The Big Choice
The professor returned after the break. “Which subject for the anal evaluation?”
The words hit like a weight. My pulse jumped, the monitors chirping to confirm it. Memories flashed — discomfort, recoil, instinct telling me no.
I didn’t want to do it, but I was willing. Smaller meant less chance of pain. I chose B-17.
The professor made a note. “Put your mind at ease, X-1; this evaluation was never about penetration. Only your choice and reaction. Both were sufficient.”
Relief loosened my shoulders. It wasn’t about dodging the act itself, not exactly. It was knowing the decision had been mine.
Chapter 7: Receiving Oral
The professor made a note on the clipboard, then glanced at the female attendant, the same one who had been quietly helping since the start.
“This is Subject N-12,” they said. “She has been assisting in a professional capacity, but she is also a prepared participant in this study.”
I looked at her as if for the first time. Tall, poised, stunning. The lab coat hinted at curves underneath, just enough to spark my imagination. She gave me a smile.
The professor turned back to me. “For this evaluation, you may choose B-17, Subject S-3, or Subject N-12.”
Hearing her referred to like that, as a designation, somehow made her more intriguing. Women knew women’s bodies. In porn, lesbian scenes always looked so tuned in, like the partners just understood each other.
I was sure I would have chosen her immediately at the start, but I found my mind wandering. I thought of S-3. The way he moved. The confidence he carried. I wanted to know what it would feel like from him. And maybe, deep down, I already knew he was the one I’d want for the final test too.
“S-3,” I said. And I was sure I saw some disappointment in N-12’s eyes.
He stepped forward without hesitation. For the first time, the chair beneath me moved, motors humming as it reclined me back. My legs spread into padded supports, perfectly angled, no strain, no effort, like the chair had been designed for this moment.
The first touch of his mouth was warm and deliberate. His lips parted, tongue sliding slowly across me. Heat followed, his breath lingering where his mouth had been, making the next stroke sharper.
He didn’t rush. He alternated between long, slow sweeps and small, focused flicks that built pressure until my hips pushed toward him. His hands rested lightly on my thighs, not pinning me, just steadying himself. The warmth of his palms spread through my skin.
Then he shifted the angle, and the contact changed. Shorter strokes, faster now, paired with gentle suction that made my legs tense hard against the supports. The sensation coiled inside me, tighter and tighter until it snapped.
The orgasm broke sudden and sharp, spilling through me in waves. My body shook, breath catching, shivers running until I thought I’d fall apart.
When it faded, I lay back against the chair, chest heaving. The thought came clear, simple, undeniable. Male orgasms were better.
“It was good,” I managed between breaths. “Really good. But men have better orgasms. Now you know.”
From the side, attendant N-12 spoke softly. “That’s because you chose poorly.”
The professor’s look silenced her at once.
I considered what she said. Maybe it could have been done better, but I still didn’t think the orgasm was as good as what I experienced as a man.
Chapter 8: Intercourse
“Final evaluation,” the professor said. “Penile-vaginal intercourse. You may choose B-17 or S-3.”
The answer came out of me too fast. “S-3.”
I didn’t know why I wanted it so much. Or maybe I did, and I just didn’t want to admit it.
The chair moved again, motors humming as it tilted me back into a near-flat recline. My legs lifted into padded supports that spread me open in a way that felt natural, almost too natural, like the whole thing had been built for this one act.
S-3 stepped forward. Calm. Deliberate. His cock was already hard. The sight of it made my breath catch. The lab, the professor, the machines, all of it blurred. My focus narrowed to him.
The first touch was steady pressure at my entrance, warm and unrelenting. Then he pushed forward. The stretch was immediate, fuller than I had imagined, my body clenching instinctively against him. A sound slipped out of me, half gasp, half moan.
He slid deeper. It wasn’t just one point of contact; it was everywhere at once. My body tightened around him, pulling him in even as my mind reeled.
He started slow, steady. Each withdrawal left me empty, each return filled me more completely. From the inside, the rhythm was different from anything I’d known before. Not just in and out, but a constant pressure, a presence that refused to let me forget him for a second.
The pace quickened. Heat built in my core, rising fast. Then his hips shifted, the angle changing, and the spark became a flood. It wound tight, too tight, until it broke open.
The orgasm tore through me in deep waves, clenching around him, holding him in place. It wasn’t sharp like before. It was rolling, relentless, my body refusing to stop even as I gasped and moaned.
Before the last tremors faded, his rhythm changed again. Harder now, deeper. Then he pulsed inside me, hot and sudden. Each spurt drew another reflex from me, my body squeezing back. A second orgasm ripped loose, smaller but sharp, layered on top of the first.
When he finally stilled, we were both breathing hard. My legs were heavy in the supports. The chair held me like it knew I couldn’t hold myself.
“It’s better!” I said, still breathing hard, “so much better. I never knew it could be like that!”
Above the sound of my heartbeat, the professor’s pen scratched the clipboard. Detached. Clinical. As if we hadn’t just shattered something no one else had ever felt before.
“That concludes the testing,” they said.
I swallowed, still catching my breath. “Can I stay this way?”
“Not at this time,” the professor replied. “We need more trials before that can be considered. But you will always be the first.”
The reversal came the same way as before. Unconscious.
Chapter 9: Epilogue
The reversal process for me was similar to the initial transformation. I was asleep, and then it was complete, and I was me again. I got back into my clothes and made my way to the exit. A new attendant was there and gave me a folder. She explained that there were numbers for reporters who were interested in interviewing me.
When I stepped outside, the air felt warm and bright. The campus was alive with chatter, footsteps echoing across the quad, the buzz of a normal day. For a moment, I wondered if I had imagined it all. The lab. The tests. S-3’s steady hands. The heat of him inside me.
I was halfway across the quad when someone called out.
“Hey!”
I turned. N-12 was weaving through the crowd, sunlight catching the pale shine of her hair. She smiled easily, like we were old friends running into each other by chance.
“Are you busy this afternoon?” she asked.
“No,” I said, surprised by how casually she asked.
“B-17 and S-3 have no idea who you are or what you look like as a male,” she went on. “But I knew who to look for out here.”
She took my hand without hesitation, and together we started walking toward the center of campus.
“My name is Kerry,” she said.
“I’m Jerry,” I answered.
We both laughed at the rhyme, quick and unforced, cutting through the noise around us.
I should have been focused on her. She was confident, beautiful, and she had chosen me out of a crowd.
But at the back of my mind, uninvited and stubborn, was the image of S-3. The weight of his body. The sound of his breath. The way I had felt with him still inside me.
“Lingering hormones,” I told myself in the professor’s voice. That had to be it. Over time my testosterone would win the battle, and I’d never think about S-3 again.
The thought followed me into the crowd, warm and impossible to shake.
The End
