While Bryan went to the bathroom, Sara fiddled around with his profile. Her 20 year old brother was cute, in his way, and much cuter now that he was nicely toned. Just for fun, Sara decided to really go to town on him - after all, as long as she was just playing around, and didn't click "accept", everything was fine, right?
Of course everything was fine. First, Sara added some height to Brian's body, until he was an impressive six-foot-three. But that made him very skinny, so she started adding muscle to balance it out. But she got a little carried away, and just kept adding it, until his computer representation looked like a bodybuilder. Sara giggled, and then noticed that Brian's other equipment looked a little scrawny on this new, big body. She giggled again, as she gave him a cock and balls to make a porn star weep with jealousy.
Sara then noticed some extra mental alterations off to the side. "Mindslave?" she muttered, "What's this?"
She clicked it, and a box labeled "Master" popped up. There was a list of names, and hers was at the top. She clicked it, and then clicked "OK" on the master box.
Sara looked at the little, 3-D image that she had created. She was curious what the changes would be like, but didn't dare try to find out. She couldn't do that to Bryan--he was her brother, after all. Then again, she could always change him back...
...Sara clicked "Accept".
Just as Bryan walked in the room.
"What did you..." he started to ask, before doubling over in pain. Slowly, he straightened, his body lengthening and thickening, as Bryan grew taller and stronger, his clothing being stretched and strained by the swelling muscles underneath. After a minute, it was done, and Bryan stood in the center of the room, tall and massive, his body thick with muscle, his huge cock and balls straining the crotch of his pants.