Jen already had the perfect revenge for Kyle that would also let her have an upper hand on him. He sealed his destiny the moment he said "transform".
"You will slowly become a trap, famously known as the city's fucktoy. Your body will become more and more feminine, ending up when your ass and hips are the biggest around town, you hair is touching your butt, your waist is thin, with no trace of muscle, a extremely girly face and very slutty behaviour and manners. You will keep your cock: In fact, you'll also have the biggest cock in town, with 10 inches of pure, sensitive, sexy, rock-hard dick, and balls the size of tennis balls. However, you'll never be able to cum with them anymore, even in it's forever hard state. You'll only reach orgasm when being fucked in the ass..."
"WHAT? WHAT DO YOU THINK..."
"I'M NOT FINISHED!" Jen firmly stopped him from saying anything, and she could almost see the desperate look in his face. She imagined he was on the loudspeaker, because all laughter subsided when she begun speaking. "Anyways" she continued, changing to a more manageable and enticing tone, just for the irony of the situation "In the course of a week, your body will change, and so will your mind. You'll see yourself becoming more and more like a whore who can't help but expose your beautiful body for anyone with slutty girly clothes that reveal ALL your assets. Boys, girls, teachers, outsiders, everyone soon will be drooling over you, and fucking you day and night. Everybody will know about it, and everybody will love it and find it natural to treat you like a complete fucktoy. You'll not like it in the begining, but will immediatly be addicted to being fucked with, eventually growing out of the controlled state and being permanently changed to a total slut. Some people will still like to make you fuck them as a power-bottom or something, then they will be able to decide when you will cum. And damn, will it be lots of cum. Any and all cum will taste delicious to you, and eventually you'll only be able to eat cum, or cum-covered food. And the sexuality of the person will not matter: You'll be universally loved and fucked buy anyone. Nobody will think it's weird, and I'll be completely imune to it, as well as anyone I choose at will at anytime. Also, you'll obey especially to me" She laughed.