Bill is surprised, to say the least, to see Ashley's face in the mirror. He doesn't want to be Ashley; he wants to fuck Ashley. And being Ashley doesn't seem like the best way to do that.
Then again....
Grabbing the powder, he heads up the stairs and gets into his car, happy that nobody saw him. He backs out, and races toward school. He knows Ashley has cheerleading practice, and he thinks he can use this to his advantage. With this powder, he can maybe talk to some of her friends, find out what they think she'd like. Or maybe he can transform into one of her friends, and talk to her. He's still working it out in his head as he pulls into the school parking lot.
He walks through the school, greeting the "Hi, Ashleys" with an attempt at haughty disdain, as Ashley would. As he passes the lockers, he sees Ashley coming through the door in the distance.
"Yikes!" he says, diving into the girls' locker room. He quickly scans the banks of lockers, seeing a bank of lockers in the corner that appear to be set up for the cheerleaders, one of which is helpfully decorated with a cheery "Ashley B" sign. He runs to the locker, which Ashley has inexplicably left open, and he opens it up.
He's not sure what he's doing, especially as he hears the cheerleaders in the background. He's going to get caught, and...well, it'll be weird, that's for sure. Quickly, he inhales some powder, and staring into the locker, just thinks, "I don't want to be found."
Suddenly, the world goes cockeyed. He's laying down inside the locker, which slams shut. Moments later, it opens again, and Ashley is there, only she's enormous. What's going on?