Another mature one
A policeman comes up to a drunken man on the street and says, "May I help you Sir?"
The drunk responds, "Yeah officer, somebody stole my car."
"Where was your car?"
"Right here on the end of this key."
"I think you'd better come down to the station with me for the night. By the way, you'd better zip up your trousers."
The drunk looks down at the unzipped fly and cries, "Oh no, they stole my girlfriend too."