Two ducks check into a hotel for a dirty weekend. They get up to their room, only to discover they've no condoms. "No problem," quacks the male, "I'll just call down to room service and get them to bring one up."
A few minutes later, room service is knocking at the door. The male duck waddles over, takes the condom and tips the lad.
"Sir," asks the man, before leaving, "should I put that on your bill?"
"Christ no!" quacks the duck, startled, "what do you think I am, some kind of pervert?!"