Jeff got done with his shower and went back to his room, a towel wrapped around his waist. He saw his sister Rosie was now watching one of her Strawberry Shortcack tapes in the living room, not even looking up as he walked through.
At the Chronivac, Jeff decided to play around a bit. Rosie's settings were still up, so he clicked a few things at random. He increased breast size to D-cup, just for a giggle, and watched the chest measurment increase to 32"
Curious, he clicked on a Panel that said "package". The package panel showed Jeff all sorts of animal changes, as well as hybrids. He clicked on "cat-girl" pretty much at random (okay, not at random - he thought catgirls were hot).
When Jeff dragged his mouse across "gender", a popup window showed up, reading "Virgin/Prepubescent Toggle" and it was set at "On". Without thinking, he swithced it to "off" and when the popup closed, he saw he had accidentally clicked "gender" changing the setting to "Male/Female".
Jeff noticed a new series of panels, obviously switched on by his changing the virgin toggle since they all related to sex. The "libido" slider setting was average, the "orientation" slider was almost to the end of "hetero", and the "resistance" slider was high. Without thinking, he slammed them all the was to the right, except the Orientation which was already there, which he slid to the middle. The new settings were Maximum Libido, Bisexual, and No Reeistance.
Jeff heard a squeal and went out into the living room to investigate. On the floor in front of the TV was his little sister Rosie - but changed.
Her perfect round tits were about to bust out of her t-shirt, despite the fact she was still 3'8" and child-sized. She had cat-ears and a tail that was swishing about madly, as well as light golden fur the same color ars her hair all over her body. Her shorts and panties were around her ankles, and her hands were busy - one on a firm cock, the other buried in her pussy, and both were working like mad. The little cat-girl moaned with the pleasure she was giving herself.
Jeff's cock was hard as a rock as he stared at what Rosie had become. Letting his towel fall off, he got on his knees and began playing with her tits, large and round, yet small enough to fit into his hand. She gave a moan of enjoyment, her hands busy until he began to huff and puff and Jeff felt his chest getting splattered. He glanced down and noticed that his sister's cock had spewed sprem onto his chest and belly.
The whole situation was too hot to think in, so Jeff didn't. Instead, he sat up and pulled his sister's hands away from her mutated genitalia. She looked at him expectantly, as if silently begging for something.
Jeff gasped as his cock entered her pussy. There was no resistance, and the girl mewed in pleasure, her tiny hips surging up, trying to bury him deeper in her. It was the tightest, hottest pussy Jeff had ever fucked. He pumped into her, trying to fir himself entirely into her with each stroke as she clung onto him and mewed her pleasure.
"More," she squeaked. "More ... more ..."
Jeff's body entirely covered Rosie as he fucked with mad abandon. Then her pussy began to spasm around his dick, and her cries became shouts, and Jeff knew his sister was cumming. With a groan, he shot his load into her, cumming like never before.
Jeff rolled off of his cat-girl sister, totally spent. And when she got up and tried to stick her three-inch cock into his groin, he thought, "Why not?"
He took her in his arms and rubbed his fingers in Rosie's pussy-slit, getting a rich purr from her. Then he smeared the sticky love-juices on her small cock. Putting her down, he put a couch cushion under his pelvis and stuck his ass up. "In there," he said.
Getting the idea, Rosie got behind him and began poking her little hard-on at his asshole. This was a new experience for both of them, and Jeff was surprised to find he actually liked the sensation as the sex-slick boydick slid into him. Hearing his little sister gasp and breathe heavy as she pumped his asshole was sexy, too. When she yowled and came inside him, Jeff found that he was disappointed that it was over.
When she slid out of him, Jeff looked back at his sister and noticed her going to sleep. Glancing at the clock, he noticed that his mom was going to be home soon. Getting up, he went back to the Chronovac and hit the "Save" button (no way was he going to deprive himself of sex like that, even if she was his sister!) and reset her to normal ...
Or tried to. While everything went back to normal, the Virgin toggle refused to budge. And the settings still showed Maximum Libido, Bisexual, and No Reeistance. Flipping through the manual, he found out that the "virgin" settings were useless once the subject was no longer a virgin. And the sex-based settings were stuck due to a bug in the software that only showed when the virgin toggle was used and the subject lost their virginity.
Jeff pondered this - it porbably wasn't too bad. He looked in the living room and Ropsie was back to normal size, species, and gender, with sperm coming out of her pussy. He took her to her room and cleaned her up, and she awoke and blew him a kiss.
Back in his room, Jeff experimented on himself, changing gender and species and back again. He gave his sister back her penis (he decided that he liked it enough to make it permanent). He also found a "fetish" listing (his own settings had 'furry', 'dominate', and 'incest').
As his mother drove up he scanned her out his window. Calling up his mother's settings, he found, Caucasian, 35, Female, 5'8", breast size 36B, 145lbs, 36" chest, 30" waist, 35" hips, 32" legs. But her sexuality readings were a shocker. She was listed as high libido, lesbian, and low resistance! And the 'fetish' settings listed 'submission' 'humiliation' and 'mild masochism - spanking'!
Jeff had had no idea about his mother. And the knowledge made him hard as a rock.