Show him.

You want to fuck him and he obviously wants to fuck you but some how you don’t feel right doing it. Not knowing what to do you reach down and unzip the boots and let them fall to the floor. As soon as the second boot leaves your foot you pop back to your original form and the spell breaks allowing both of you to think once again. You lean back against the desk, now fully male, and shake your head to clear the last lingering cobwebs in your head. You see he does the same and stares at you with disbelief.