The locker room was dark and everyone had already left. Hugo reached into John's back pack and pulled out a sub beastman vial. Without much ado Hugo downed the milky white substance. John just sat there a little bit dazed at how well things were going.
But then he snapped out of it and quickly turned to Hugo, who had just changed into his regular clothing. "Hey, Hugo, How do you feel?"
Hugo shook his head, "I dunno, I feel weird... I want more... but not from a vial...from you!"
Suddenly the fly of Hugo's jeans popped open and a massive, fully-errect over-sized dick burst out. Hugo reached down to touch it and let out a low moan as it began to drip pre down the curve of his shaft at the slightest touch. Hugo snorted and his face contorted with pleasure, "FUCK!" The seam of hid pants ripped open as two giant hairy balls popped into their place between his thighs in Hugo's hairy nutsac.
"Oh god... It feels... SO good" Hugo said between huffs.
Hugo began to stroke his over-sized member with his two human hands. As John watched he could see the hands get larger, stronger, and hairier. Hugo's whole body started to change, getting bigger. His once large human muscles were swelling with mass and fiber as he grew beyond the limits of most body builders. Only Hugo's heavy-set Jock formed remained, his new expanding muscles covered by a later of fat and thick flesh.
His pants split as his large bulbous ass swelled revealing the tight white briefs beneath covered in stretch marks. Hugo began thrashing around leaving large dents in the lockers on either side of him.
He roared and ripped off the shreds of his pants, tossing them aside as new thick powerful thighs felt the air.
Hugo was definitely becoming less Human. His feet tore through his expensive (but shoddily made) sneakers and continued to keep growing his hands also grew disproportionately to his body which aided him in the massive task of jerking off his new shlong. His thick body hair was growing into a thick black fur, covering his light skin glistening with sweat. His muscular shoulders grew wider and his arms grew longer. His brow became thick like a caveman's as his lower jaw jutted out two monstrous tusks. His ears became pointed and his wavy black hair rolled down over his shoulders. As he thrashed about his shirt became attached to a destroyed locker and it tore off, revealing a massive woolly chest with pecs bigger than John's head.
Hugo was fucking huge now, His two massive muscular buns had to squeeze to feet between the lockers, and he was easily seven feet tall.
Hugo straddled a bench and stared at John, evidently forgetting about his transformation, and proceeded to jack-off.
"Hugo like John scent.....John...nice bod...." Hugo rumbled with a deep voice.
With a deep moan Hugo felt his first release as a beast-man. He shot his cum to the ceiling where it stayed. And then he shot some more. After he was done with his Load Hugo started sniffing John some more.