I was asked to dress Zu up in a PowerPuff Girls costume. Unfortunately, Zu did not realize she was supposed to wear her own underwear, since there was no such part of the costume.

When I look at this picture, all I can see in my head is Zu getting sandviched in some bathroom stall at some sort of convention.
You see a different scenario? Why not share it, perhaps your scenario really captivates some other guy to jerk it to this even harder!