Numerous Body Swap Stories

The Growth Potion by thetfchangingroom

I'd been lured to Ryan's apartment under the pretense of trying out some of the experimental potion he'd been using to get himself jacked. Ryan was easily the biggest guy at the gym, and once day in the locker room we struck up a conversation. He told me he'd been using this secret drug that gets his muscles super big in a short amount of time. I didn't believe him initially, which is why he asked be back to his apartment to try it out.
It didn't take too much convincing. Ryan was easily the hottest guy at the gym. Not only were his muscles perfectly sculpted, but he had a gruff, scruffy aura about him that I just found instantly attractive. His body was covered in thick brown hair, which bushed itself around his face (and his cock).
He lived in a small apartment outside of town, and although it was pretty big, it was also pretty secluded. As we got out of his car and walked up to the door, I began to realize I had no idea what I'd just gotten myself into. Still, I was transfixed by his body, his ass giggling in his tight gym shorts as he walked into the apartment and tossed his keys down.
"Take a seat," he said, motioning to a couch, "you want something to drink?"
"Water," I said, and he disappeared into the kitchen. I looked around to see the place was pretty sparse. There was nothing really breakable, and all the stuff that possibly could have been, like the glass on top of the coffee table, was curiously absent.
Just as I was beginning to suspect something else was going on, Ryan walked back in with a glass of water. "Here," he said, "drink up." I did. I was surprisingly thirsty (in both senses of the word) and the water tasted really good. Abnormally good.
I looked up at him. "Did you put something in this?" I asked.
Ryan just grinned. "You said you wanted to see about that formula right?" Oh no. Before I could even realize what was going on, I felt my body get suddenly sweaty. I froze in fear as Ryan reached over to take the glass from my hand. "You might want to lay down for a minute before it kicks in. I gave you more than the usual amount, so I'm not exactly sure what's going to happen."
"Wait... what??" I could barely speak through the heat by body was radiating. "How... much... more?"
"A triple dosage. You're my guinea pig man! That's why I had you come over."
I couldn't believe what was happening. I had been tricked, against my will, into the house of some stranger who was about to turn me into a muscle beast. Frantically, I tried to run to the door, but I only ended up down on the floor on my hands and knees, panting vigorously.
I heard Ryan get up and circle over to me. All I could see was his shadow on the ground, and all I could feel was an aching soreness that had overtaken my entire body. "What's... happening... to me?"
"You're sore right now, aren't you?" I nodded. "Good. That means it's taking effect. You might want to take off those clothes. Assuming you want to keep them in one piece." I couldn't believe I was even listening to him. And yet, I managed to get my shirt and my shorts off before falling back down on my forearms.
I'd never felt anything like this before. The extreme heat pouring sweat from by every pore, every single one of my muscles tensing as if clenching into a fist.
And that's when it started to happen. I felt by body begin to grow heavy. At first I thought it was the sweat, but when I looked down, I saw the muscles on my body were growing. Inflating slowly with every heart beat, like pumping a balloon.
Ryan laughed and flopped down on the couch in front of me. He'd already taken off his shirt, and he was now removing his shorts, starting to stroke his massive bodybuilder cock as he watched me transform into his ultimate fantasy. "Yeah," he said jacking himself, "that's it boy. Keep growing."
I wanted to tell him off, but another wave of soreness hit me. But it was different this time. It was a painful pleasure, and this time I could literally feel the muscles stretching beneath my expanding skin. "GrrrrrraaAAAAGGGGG," I bellowed in a much deeper voice. I felt my arms press against the carpet as by body continually expanded. By now, I was big enough that I was pushing the coffee table away from me. This must be why he took the glass off, I thought. Man, I must be as big as him now.
The idea excited me. To think I was as big as the biggest guy in out gym, in just a matter of minutes! Suddenly, I was envisioning Ryan and I together, two big muscle hunks in bed, fucking and jacking each other off.
Maybe thinking about this wasn't the best idea, because the new wave of heat I felt was around my crotch. I looked in between my legs, and although my ever expanding pecs were obstructing the view, I could just make out the head of my cock reaching out as my erection got bigger and bigger.