David turned up the volume on the TV as some noises came from their father and step-father's bedroom. They were not quiet lovers but David and Katie always did their best to ignore it. They were glad their father was happy and Jeff was a great step-dad. He had come to feel like part of the family, what was having to ignore a little fun time. When things finally quieted down Katie hopped off the couch.
"Where you going, squirt?" David said with a grin, still watching the game on TV.
"To do some homework, and stop calling me that!" Katie threw a pillow at David before making her way to the stairs. She was definitely glad her father was happy, but sometimes she hated being the only girl in the house. Though as she was heading up to her room something caught her eye from the office where her dad and Jeff kept their computers. Something was flashing on the screen of Jeff's computer. Curious, she walked into the office and peered at the screen. "Change Complete"? What did that even mean?
She wasn't worried either her dad or step-dad would walk in on her. They'd probably spend the rest of the evening cloistered in the bedroom. So she sat down in Jeff's desk chair and cleared the alert. She was shocked by what she saw, though didn't quite know what to make of it. A program to change things about a person? She noticed Jeff's stats were up on the screen, but nothing to indicate what he had been changing, though it had a shockingly accurate depiction of him in 3-D, with more bits visible than Katie really wanted to see.
She was about to leave, not wanting to mess with the strange program when her thought about hating being the only girl in the house came back to her. She could make David her sister.. or Jeff her mom.. but something about messing with other people just didn't sit right with her. There was another option though, she could make herself a boy.
What was she thinking, like this thing would even work. But.. it could be fun to play around with. Getting up from the chair she went to close the office door, then headed back to the computer. She found the program had four individuals available, including herself, her brother, and both her dad and step-dad. She brought up her own stats, her eyes widening at the accuracy of it. Jeff wasn't a creep at all, but somehow this program had gotten everything about her, maybe something in the program could scan people. Made as much sense as anything else.
She changed her gender to male. The image changing to what looked like David when he was her age. There were a few differences, but they looked a lot alike. Katie was getting a little weirded out by the program, but more curious as well. She changed the age of the virtual boy-her to 18, same as David. The image aged up in front of her, and while not twins, boy-her and David looked even closer than before.
What if..? It wasn't on the main stats, but she found it buried a little deeper. What if her father was her step dad Jeff instead of her actual dad? She made the change, and as she did the image on the screen shifted quite a bit. Both her and David took strongly after their father, but with the change the image on the screen now looked like a much younger version of Jeff. Tall and muscular, though a bit more lean than the burly strength her step-dad possessed. Youthful. She had seen plenty of old pictures of her step-dad to know this figure looked almost exactly like him.
"What you doing, squirt?" Katie panicked and closed out the program immediately on hearing her brother's voice. She hadn't even noticed him opening the door. Nor did she notice she clicked 'Save & Exit' instead of just 'Exit'.
"Nothing! I need to print something out for school from my email." It was a good excuse, the only printer in the house was in this room. She sheepishly opened her email and just hit print on some random thing. David wouldn't check that closely.
She could tell from the look on his face he didn't quite believe her. Too bad she didn't get a better look at the creation she had made. But she grabbed the sheet of paper off the printer, moved past her smirking brother, and headed back to her room. She really did have homework to do, and sat down at her own desk and computer to start working on it.
She couldn't seem to focus though. The words seemed to swim on the page in front of her like even the book couldn't decide what it was supposed to be about. She felt warm, too, despite her ceiling fan being on. Maybe she just needed to move a little. Standing up, she had to put a hand on her desk to stop from swaying. Everything looked... lower than she was used to. No. She was taller!
She looked down at herself, expecting to see her shorts and shirt riding up on her, but they still seemed to fit. Actually, her shorts looked longer. They used to end at her upper thigh, but now they reached almost down to her knees. Her tank top looked a little bigger and baggier on her as well, her clothes just over all less feminine.
What was going on?! Could the program have actually been real? Was she becoming..?! Hair fell into her eyes so she reached up to brush it behind her ear, except it wasn't long enough anymore to tuck back. She quickly grabbed a few strands and pulled them to check their length, only a few inches and still shrinking. Scrambling over to her closet mirror, she saw the hair that temporarily blocked her vision was retreating out of her eyes as it shortened to a short, slightly-spiky style.
The front of her shirt was flattening out, her breasts having disappeared. She ripped off her tank top and threw it aside, shocked as even her bra had vanished. Her chest hadn't been this flat since she was ten. No trace of her womanly growths remained. Looking at herself in the mirror she very much looked like a young teenage boy. Even her cropped shorts were now a more masculine pair of cargo shorts. With a shock she noticed that her legs looked a bit darker, and it wasn't that her skin tone changed, but dark hairs that had grown out over her shins.
She had to reach out and brace herself with a hand on the wall as another growth spurt shot through her, adding a handful more inches in height, he shoulders broadening as he hands and feet got bigger. A tuft of dark hair sticking out from her previously smooth arm pits. The feminine softness in her facial features began to disappear, too. But they also seemed to be changing, not just becoming more masculine. Her brows thickened as he jaw squared out, her nose becoming a bit more prominent in the middle of her face. She was coming to resemble Jeff's stronger masculine features. A bit of a shadow formed on her upper lip and chin, side burns growing in down in front of her ear as the shadow spread along the line of her jaw to meet them.
Even as the though went through her head, she was having trouble thinking of Jeff as her step-dad rather than her biological father. Thinking of 'dad' brought his face to mind first rather than Mike's. Her form was filling out. Her now flat chest was beginning to push out again, though this time with muscle rather than breasts. She felt more steady on her feet as muscle packed in on her legs and the arm bracing her on the wall. She watched as her abs seemed to sculpt themselves out of nothing into a tight six pack. Muscle was growing in heavy and dense, still mostly lean from youth but the start of becoming a physically powerful body-builder like her father.
A line of dark hair grew up the middle of her stomach a few inches past her navel, as a light dusting of dark hair grew in a V pattern along her pectorals. She new she had set the program to age her to eighteen, but she almost looked like she could pass for twenty. A sudden strange feeling between her legs had her working at the button of her shorts. Finally undoing it, they fell to the floor. Her panties had changed to a pair of boxer-briefs which she quickly shucked. A nub had formed between her legs, and a quick check with her fingers met with only unbroken skin where her womanhood had once been.The nub of flesh was quickly growing, taking on a familiar shape from sex-ed class and the few times she had messed around with her boyfriend.
There was nothing left of 'her' now. Katie was a 'he' plain and simple. With a wince, he felt his balls suddenly drop, the empty scrotum that had grown in under the growing cock suddenly holding a pair of small testicles, though they, lick the cock, were growing bigger by the minute. He knew his dad.. Jeff.. his dad was packing, and obviously he took after him. His new cock went completely rigid, the foreskin that had covered the head pulling back behind the glans. He shivered as he ran a hand over his new tool, feeling it both for the first time and knowing from memories that were flooding into him that this was hardly the first time. Not even close. But he let himself go, letting the now nine-inch cock stick out proudly on it's own, his two golf ball sized testicles hanging low in his sack.
Even his room had changed around him. Weights sat in one corner, athletic gear from the few sports he played in another. Any trace of girly things in his room had vanished, the makeup and vanity he had once had now a shelf full of trophies. The fear he had been feeling at the change slowly ebbed away to an easy confidence. This is what he had wanted, wasn't it? To be one of the guys. He struck a few poses in the mirror, admiring the young, eighteen year-old stud he had become. He wasn't Katie anymore. Carter. That was his name. Carter Kendrick.
He heard someone suddenly clearing their throat from his bedroom doorway.