A man finds his seat in the theater, but it's too far from the stage. 

He whispers to the usher, "This is a mystery and I have to watch a mystery close up.  Get me a better seat, and I'll give you a handsome tip."

The usher moves him to the second row, and the man hands the usher a quarter. 

The usher looks at the quarter and then leans over and whispers, "The wife did it."