While not the most common there was a high school tradition that if two same sex friends were dateless one would change sex and they'd go to the prom together... Of course it'd take half the school year for one of them to change back, but that was the tradition... and as such...
"No you become a girl!" Drist demanded!
"Hey, you were a girl once change back!" Peron exclaimed!
Drist had been a girl once, but was always more of a tomgirl and changed to a guy and never went back. He never liked his family's asian tea ceremonies and the like, and preferred trying out swordplay and the like. Peron on the other hand was just a dude all the way round. Having lived near the sea for awhile he surfed, did a few weights, and was really comfortable with his manliness. While the argument started as a joke, and there was nothing binding either of them to a sex change... Well when they envisioned going to the prom with either an Asian cutie, or a big titted blonde both kinda wanted the tradition to happen.
The two tried choosing which would be the girl with... Arm wrestling... then cards for a best 2 out of 3... and then video games... and then... The two eventually came to a decision as in the end the person turning into a girl would be