“Beginning phase five.” Shit.
Charlie sneered back, and said “this.” With that, he broke the pin, and the boys were wrestling again. This time it got harder and harder for Lee as it went, and before he knew it he was pinned by a growing Charlie.
He saw Charlie draw his beefy arm back for a punch, and screamed “Wait!” just moments before Charlie's fist connected with his cheek.
“Yes?” said Charlie.
“You need me. To stop the machine. It takes two people to press the buttons.”
Charlie looked thoughtful. “Alright, then stop it now.” Lee hesitated. “It looks like you need a little convincing.” Charlie's other first slammed into his other cheek.
“Stop!” he plead.
“Why?”
“Or I'll- I'll beat you up.” Lee pressed on into the silence left by Charlie's hesitation. “Each round I grow more and you shrink more. This is the last time you'll be bigger than me. Soon I'll tower over you and if I'm angry that's going to be a bad situation for you.” A pause. The pump clicked on, and Charlie grudgingly got off Lee, and even held out a hand to help him up.
Lee took Charlie's hand, and pulled himself up. The two stood close to each other for a moment, standing eye-to-eye. But it couldn't last long, because Lee was rising ever higher over Charlie's shrinking frame. Charlie broke off, turned around, and walked a few steps away.
That left Lee a chance to examine his body, a chance he hadn't had in a while. He was Big. Almost six and a half feet tall, built like a bodybuilder, and his cock – thicker than his wrist – was pressing up against his pecs, as Charlie's had at his peak. But as he watched, his cock grew too long to be constrained by his pecs, and slipped out from under them and began sliding up the deep crevasse between them. He was not only bigger than Charlie, he was bigger than Charlie had ever been or would ever be.
The pump clicked off, and Lee took his eyes off himself to verify that yes, as per his calculations, Charlie was the same size he was this morning. “Alright, look, I'm back to my normal size. It's over. Can we push the buttons to stop this thing now?”