Two boys go in to use the bathroom and find that two girls from their class are also hiding in the boys' bathroom. They laugh together and convince each other to play a game of "show me yours and I'll show you mine". After a while they get caught and scolded by their principal.
The boys are skinny dipping fishing using their penis for worms to catch the fish. One boy does successfully catch a fish while another boy is caught by a crab.