Explore your new body more

The former Katie, now transformed into her older sister's boyfriend David by putting on the David suit created from him by a zap from the black "pen," tries not to giggle as he admires his nicely-muscled chest in the mirror.

Giggling just wasn't in character for David, and he was the only David now. The other "pen," the brown one, was supposed to provide suitable memories to anyone who was wearing a suit created with the black one. It would be more fun not to use it and just act like David as best he could, but much easier to zap his newly male self and have proper David behavior and knowledge. He thought about it while he got dressed. It was odd but strangely right to put on boy clothes, particularly these big shoes!

The fake David goes to Katie's room, gets the brown "pen," and: