Mark grinned as he poured in a couple doses of the male vial. He honestly wasn't sure what to expect. He'd been a woman when he started, and now he was a ripped, hairy, 6'5'' giant of a man, dwarfing his slim 6'' boyfriend with ease. And while the prospect of shoving his huge penis up his ass seemed tantalizing he was curious to see what would happen if a man took the same dosage as he had.
"Here," Mark said, handing his boyfriend the spiked beer. Despite being a very large and very sexy man, Mark couldn't help but still find Greg attractive. He wasn't stellar, but he was still cute, and he slung a huge arm around the smaller man's shoulders.
After about fifteen minutes Greg had downed all of his beer and Mark watched in amazement as a weird expression crossed his boyfriend's face. "Are you okay Greg?" Mark asked, almost losing his act.
"I'm fine," Greg said, though he felt weird. A tingling sensation was spreading all across his body and then suddenly he felt his whole body convulse and causing him to drop to his knees. He saw his arms had doubled in size, the muscles growing right in front of his eyes. He got to his feet and saw Mark was standing. While before Greg's head had reached the bottom of Mark's chin, Greg now found himself looking eye-to-eye with him.
The tingling hadn't gone anywhere though and Greg could feel himself inching upwards in height and his clothes getting extremely tight as his muscles swelled to massive proportions. Then he convulsed again and again; his muscles becoming twice the size of Mark's, each a solid steel cord with his torso becoming a finely toned mass of steel-hard pecs and solid, well toned abs in an eight-pack configuration. His penis, already about six inches long erect, grew to almost fifteen and balls at least the size of oranges, which would have seemed ridiculously oversized, but it was offset by Greg's height which was pushing past seven inches.
His face reformed to become a rugged, thick jawed visage and the light hair all across his body thickened incredibly, forming a huge, heavy beard, a forest around his massive privates, and covering his gigantic muscles. Greg's clothes had, by now, become nothing but shreds on the floor as he continued becoming larger and more masculine, his figure broadening and becoming more sturdy and heavy-set.
Then the changes stopped and Greg, formerly dwarfed by Mark, was now the dwarfer, while Mark was the dwarfee. Greg stood at least eight feet tall with gigantic muscles that would make Mr. Olympia shriek in fright at the sight of, heavy hair all across his body that made lumberjacks look hairless, and junk that made a porn star's look juvenile. Mark was now looking at the base of his boyfriend's giant pecs and felt suddenly quite small. "What the fuck happened?" Greg asked, his voice a deep baritone that made James Earl Jones sound like a school girl. He looked down at Mark and angrily grabbed him by the front of his robe and hauled him easily off his feet. "You did something to that beer didn't you? You big ugly fuck."
"Greg! It's me! Mary," Mark said hurriedly, hoping to avoid being pulped. "I'll show you what happened, just let me down." Greg wasn't sure, not only was he physically more masculine, but his mind had become more masculine too, and therefore more aggressive and controlling. Moments before Mark was a giant who had been intimidating him, now the tables were turned.