The magic of science

by Ultra GMan

 When Todd found out that men used to go into sexual heat, it was only minutes before he had Josh whip up a spell so that he could experience that first-hand.

Added: May 2022 1,880 words 4,139 views 4.8 stars (11 votes)


“You ready for this, Todd?” Josh said, holding out the gleaming capsule. Without saying a word I grabbed it out of his hand and gulped it down, feeling a warmth almost immediately rush over me as it began to change me. But maybe I’m getting ahead of myself.

My friend Josh and I have a few things in common. We both like sex with men. We both like to have sex with each other, although strictly in a friends-with-benefits sort of way. And we’re both interested in unlocking strange biological traits in people. Where we’re different is how we get there. I’m the science guy, who comes up with all sorts of interesting ideas that could take years or decades to even begin to figure out. Josh is the magic guy, who then can whip up a pair of magic capsules to do it instantly. (One capsule to make the change, a second one to undo it. Josh explained once that it’s part of how his magic works, I’m just glad it means if something isn’t quite what was expected we aren’t screwed.)

We’ve had some real successes in recent months, ones that have honestly boosted both of our sex lives. But I’ll talk more about those later. What matters now is that while going through some studies on human genetics, I caught a mention to something odd. The author of the paper had theorized that millennia ago, our ancestors went into heat the way that many other animals do now. Increased sexual desire that would grow until the person in question got bred, and a temporary amplification of physical attributes to make you more desirable to the ones that were going to breed you. Oh, and apparently men went into heat too.

I’m not going to lie. I love having sex, especially being topped. And in general, my sex drive is already pretty good. But there was something so hot about the idea of having your body go into sexual overdrive until you get fucked—and even better, maybe your body getting pumped up as part of it, even if temporary—that I could feel a rapidly expanding puddle of precum in my underwear. And of course, seconds later, I was on the phone with Josh.

So now I’m standing in Josh’s playroom down in his basement, gulping down the capsule, and that familiar warmth from one of Josh’s spells rolls over me. I took a deep breath, and then… nothing.

“That was anti-climactic,” I said, laughing in spite of myself.

Josh chuckled and shook his head, his slightly floppy blond curls moving back and forth in an irresistible manner. “Well, remember, you aren’t going to be in heat 24/7. You’d never get anything done. So you’ll regularly go into heat, almost a cycle.”

That made sense, even if it was disappointing. “Okay,” I said, shrugging. “How long do I have to wait for the first one?”

“It’ll be a while,” said Josh. “At least another five seconds.”

I looked up, startled, and then it hit me like a ton of bricks. Oh boy. It was a new wave of warmth running all over me, but this was different than when I had gulped down the capsule. It was stronger, and if it makes sense, somehow there was a passion behind this. I was feeling sexual, and masculine, and strong, and needing to be taken.

“Wow,” I said, taking stock of the sudden shift. “Wow, wow, wow.”

Josh had a shit-eating grin on his face. “Yeah,” he said. “And the more we wait, the better it’s gonna get.”

I shook my head. “I don’t know if I can wait,” I admitted. “I kind of want you to just take me right now.”

Josh nodded thoughtfully. “Okay,” he said. “Let me just get something upstairs.” He headed over to the stairs, and the door swung shut behind him.

Eagerly I took my clothes off, running my hands all over my arms and chest. Nothing felt different, and while I work out (mostly swimming) and look good, no one’s ever looked at me and called me muscular, if you know what I mean. I walked over to Josh’s sling that was in the playroom where I’d definitely been fucked before. Sitting down on the edge, it suddenly hit me. What exactly did he need from upstairs?

I got back up and walked over the door and turned the handle… nothing. It was locked.

Josh, you jerk.

I pulled out my phone and hit Josh’s number.

“Sorry,” he said upon picking it up. “But you’ll thank me later. Just give it five minutes.”

“Get down here and—” I started to say.



I sat back down on the sling, carefully leaning back into its support. I idly stroked my rock hard cock, even as a little voice in the back of my head said that it wasn’t what I really needed. What I needed was someone to fuck me.

As I laid back, stroking my penis with one hand, I found my other one almost absently moving over my pecs. And then, a few minutes later, it happened. There was a sudden surge of warmth in my pecs and they grew. Just a little bit at first, but I could somehow feel them almost inflating with muscle.

“Oh shit,” I whispered. This was amazing.

I looked to my biceps, just in time to see them plump up a little too. I gave off an inadvertent groan of pleasure. Looking down at my thighs, I could see them starting to beef up a little too, and my glutes were also getting bigger, denser, thicker as I rose off of the sling just a bit.

I closed my eyes and moaned again. And then, stroking myself, I felt it. My cock started to thicken and lengthen, and I could feel my balls start to churn and grow. My balls felt so heavy, I had to open my eyes and look. My package has always been pretty average, but my penis was easily an inch larger now, with some thickness to match. But my balls… oh god, my balls, they looked to be the size of oranges now, way out of proportion to the rest of me. I could almost feel the cum inside them, building up.

The wave of heat that was sweeping across my body came to a temporary stop, and I moaned again. I was so fucking sexy right now. I felt like more of a man than I ever had.

“Fuck me,” I whispered to myself.

And then, suddenly, I felt Josh’s tongue at my butt and I gave off a huge gasp, my eyes shooting open. Josh had come back in and he was eating me out, his eyes glinting with delight.

“Oh god,” I moaned. Josh used to be someone who shot way too fast in sex, and his way to compensate was to be the world’s best ass eater, and that was definitely in effect now. For what felt like a small eternity—but it was probably just a few minutes—he went to down on my ass and occasionally my overly full balls, and my hand was starting to get soaked by what was so much precum that I would have thought I’d actually started ejaculating if I didn’t know better.

But then Josh stopped, and stood up, leaning over me. He was completely naked, and his large 9.5” cock was at attention. Grabbing my hands, he pulled them over my head and started to kiss me slowly, passionately, even as that cock head that I was so familiar with was starting to push at my ass.

He stopped kissing me for a second, then half-whispered, half-growled, “Don’t you dare cum.” And with that, he pushed into me in one strong thrust.

Ohhhhhh wow. Now, like I said, Josh and I liked to have sex. And Josh is very good at sex these days, now that he no longer shoots within ten seconds. But this? This was something else. My whole body was tingling, because it knew this was what I needed, this was what I wanted, this was yes yes yes.

I gritted my teeth as Josh began to rock back and forth inside me, slow one minute, fast the next, keeping me off-guard even as waves of pleasure started to wash over me. My breath started to pick up, and Josh instantly stopped.

“Don’t you dare,” he said, watching me carefully until my breathing slowed back down. I can’t say I blamed Josh, after all. He wanted to have just as much fun as I did. Oh, and you know how I said that Josh used to come in a matter of seconds? Well, not once I told him about a genetic trait among some primates where the ones that passed on their genetic seed the most were the ones who couldn’t come until their partner did first. One spell later, and Josh simply cannot cum until the person he’s fucking does first. Once they do, mind you, it’s usually all over. That hair trigger is just turned off, it’s not gone.

We went through several cycles of this. Josh would fuck me until he thought I was getting close, then he’d stop. All was good and well… and then suddenly I felt it.

My pecs were getting warm again, and suddenly I could feel it. That inflation of muscle, that denseness increasing. Josh’s eyes got very wide, as he literally saw my muscles growing in front of him.

“Holy shit,” he whispered, and then he started frantically licking and sucking on my pecs as they grew, the nipples starting to enlarge inside his mouth. He was frantically pounding my prostate now, and I let out a guttural groan.

If Josh knew what that meant, he didn’t care, he just kept sucking and biting on my nipples, and that sent me nicely over the edge.

I always read about people shooting like a firehose, but it never seemed to make more sense as an analogy until now. The amount of cum pouring out of my penis must have been a good half-quart, as I shouted and roared as the most intense, amazing orgasm ripped through my body. And with that, Josh started shooting, and as his own semen sprayed inside me, it felt like a key had turned in a lock. That was what I needed. That was what was going let me come back down.

And so, a few minutes later, as Josh pulled out and surveyed the puddles of semen all over the rubber floor (hey, it is his playroom, what were you expecting, rugs?), he shook his head and laughed. “This is going to be a lot of fun,” he said.

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