Jake could hardly wait to get Ashley and Kelvin up to his room. He made Kelvin stand in front of the mirror. The boy was dressed in a well-worn polo shirt and athletic shorts. He wore a pair of plastic flip-flops on his feet, but they were the first things to go as Kelvin's 13-year old body began to grow into its newly appointed 18-year-old form. His feet grew to size 12's, and his legs grew longer and harder with muscle as a light dusting of hair also appeared on the darkening, tanned skin. The shorts shrunk down to running shorts, rounding out in the back around Kelvin's new bubble butt.
Kelvin's boy torso matured quickly into well-defined abs, complimented by well-developed chest muscles and crowned with dark quarter-sized nipples, and accentuated by a quite notable blond love trail that terminated at a now-considerable pubic bush. Kelvin pulled the waistband of his running shorts and saw a bronzed set of bull-like nuts hanging beneath a flaccid five inch cock, a cock which would now measure a healthy two inches wide and just slightly over eight inches long when erect. Kelvin smiled at Jake and Ashley, and began to walk towards them.
At five feet ten inches tall, a full three inches taller than when the transformation began, Kelvin presented an incredible physical picture. One that, for want of better words, resembled a darkly tanned, human-sized, replica of Michaelangelo's "David" come to life.
Ashley looked at Jake with hungry eyes, first at the massive tent in his pants (complete with a wet spot), and then into his eyes.
"That was pretty hot."
"Yeah."
"So... what are you going to do to me?"