A guy goes to a house of prostitution. He selects a girl, pays her $200 up front, and he gets undressed. She's about to take off her sheer blue negligee, when the fire alarms rings!
She runs out of the room, with his $200 still in her hand. He quickly grabs his clothes and runs out after her. He's searching the building, but the smoke gets too heavy, so he runs outside looking for her.

By this time, the firemen are there. He sees one of them and asks, "Did you see a beautiful blonde, in a sheer blue negligee, with $200 in her hand?"

The fireman says, "No!"

The guy then says, "Well if you see her, screw her. It's paid for."