Ever since puberty started Jake had wondered what he'd look like as a grown up. Not just twenty or something like that but a man his dad's age. He changed the age on the program to 35, a year younger than his father but the age ending in 5 seemed a close enough choice. He wasn't sure how accurate the image would be but he looked at the model, frowning a little as nothing happened. Then he noticed the button to start changes was highlighted.
He clicked on that, then another pop up caught his eye. Alter reality? He didn't really get what that meant, but he just agreed and clicked through, he was eager to see what would happen to the model. His cursor turned to a spinning ring as a loading bar appeared. Jake leaned back to wait, watching the monitor.
He fanned himself with his hand slightly. The room felt oddly warm. He reached up and tugged at the collar of his tee. Why did he suddenly feel so uncomfortable. His shirt felt tight, and so did his pants for that matter. Looking down, his eyes widened in shock. There was about an inch of his stomach showing between the bottom of his t-shirt and the top of his pants. And his shirt was clinging to him, but his clothes weren't shrinking, he was growing.
Quickly he tried to pull off his t-shirt from over his head, it took a bit of a struggle and his arms caught in the too small garment as he was finally getting it over his head. There was the sound of ripping fabric when he finally pulled it free and tossed it aside. His torso had started to grow some muscle as well as just getting bigger. He could make out the beginnings of chest muscles.
He felt something pop, and the sound of plastic pinging off his monitor brought his attention back down to where the fly on his jeans had burst apart. The blue denim was stretched almost painfully taut on his legs and he was starting to feel pins and needles. He hopped out of his chair and started pushing down the pants, hopping around a bit until he fell on the bed, finally able to push them down and off, exposing legs with a light dusting of brown hair growing up from his ankles to his knees. His white briefs still fit by the grace of elastic, but where starting to look a bit stretched out as well.
He scrambled off his bed and over to the mirror on his closet door. It looked like a teenager staring back at him, not his twelve year old self. Maybe fourteen or fifteen. The program wasn't changing the model, it was changing him. It was an incredulous thought, but the evidence was right there. He still looked to be on the slender side, but as he watched he added several more inches in height, his limbs stretching out giving him that gawky teenager look as he moved through his sixteenth year, his hands and feet looking just a bit too big for his body.
The brown hair growing up his legs moved past his knees and up to his thighs, and some began to grow darker on his forearms. He noticed more hair now curling over the band of his underwear, starting to grow a line up his stomach, a tall narrow triangle of brown hair slowly creeping upwards, his tight underwear tented precariously, showing the base of his cock in a thick nest of brown pubes. A look down showed him more hairs starting to grow in around his nipples and in the middle of his chest, a couple, a dozen, then a solid patch of short brown hairs. An itch under his arms made him lift them, exposing rather thick bushes growing in his pits, and that musky odor of a teenager. He looked back up to meet the gaze of a face quite a bit changed. His jaw was stronger and squared, with a strong chin. His nose which had always been a bit too big for his face now just looked bold rather than awkward, along with thick dark brows. Brown stubble was obvious on his upper lip and chin, his sideburns a bit thicker and more obvious. He could almost see his jaw darkening as his beard continued to fill in.
He started filling out as he rounded eighteen and headed to twenty. His shoulders broadening significantly as his muscles began to go from lean to brawny. His arms thickened to what his legs had once been and his legs felt like small tree trunks. His chest pushed out into two plates of muscle as curly brown hair continued to spread out along them, slowly covering them up to his collar bone and down to meet the foot wide strip of hair covering his stomach, but doing little to hide the firm, cobble-like abs he now sported. His underwear could no longer take the strain, already pushed out by his swollen manhood and finally ripped apart. His erect cock flopped free, seven inches long but girthy. He tugged the remainder of the fabric off, letting his golf ball sized balls swing low.
As he continued to age through his twenties, the changes slowed a little but were no less significant. The last traces of baby fat melted from his cheeks, leaving him with a strong, rugged face, lantern jawed and masculine. He could feel warm pre sliding down the underside of his cock as he looked at himself in the mirror. Bracing one hand on the wall he gripped his manhood in the other and began to slowly stroke. He couldn't close his fingers around the thick shaft, but that didn't matter. His exposed body hair seemed to shorten, no.. it became trimmed. Long enough to still be obvious but not too shaggy. There was full stubble on his face as well, not long enough to be called a beard, but he knew he could grow an impressive one if he wanted. But why hide that wonderfully squared jaw and chin. The stubble accented it. The hair on his head shorted to something just a bit longer than a buzzcut.
As he moved into his thirties his muscles kept growing, slow but steady. Some fine lines appeared at the edges of his eyes and around his mouth and nose, and the hand on his cock started to feel rough and calloused, which somehow felt even better on his slick, straining erection. His abs lost some of their definition, his stomach was still almost all solid muscle, but a little bit of a gut was starting in his middle, it somehow made him look stronger. He came with a deep and heavy grunt, octaves lower than his voice had been before, just as the final changes settled in. A few silvery hairs appearing at his temples and in the stubble on his chin. His cum splashed heavily against the mirror as he sighed deeply, resting his forehead on his forearm.
Jake's computer let out a small ding and he turned to look at it. The words 'Change Compete' flashed on the screen, and the model rotating in the background was identical to the man staring back at him in the mirror. A tall and powerfully built man, hairy but not overly hirsute, his shoulders and back were still blessedly smooth, even is his ass did have a light coating of brown fuzz. "I'm a fucking beast." He said, grinning at his new baritone rumble, slightly rough and husky. Even his thoughts seemed different, he didn't feel like a twelve year old in a man's body, he felt right.
Only then did he notice the room had changed around him. It wasn't a kid's room anymore. The large bed, desk, and dresser were all simple, and there were a few personal affects around, a free-weight set in the corner. The scraps of fabric from his torn clothes were just gone, and an outfit actually laid out on the bed. Jeans, a black tank that would show off his powerful arms, and a pair of black boxer briefs. The room didn't seem very lived in, but he recognized most of it as his.
He was brought out of his thoughts by a knock on the door.