Three Men in a Boat
Three men were sitting on a park bench. The one in the middle was reading a newspaper; the others were pretending to fish. They baited imaginary hooks, cast lines and reeled in their catch.
A passing policeman stopped to watch the spectacle and asked the man in the middle if he knew the other two.
"Oh yes, " he said. "They are my friends.
"In that case, " warned the officer, "you'd better get them out of here!"
"Yes, sir, " the man replied, and he began rowing furiously.