Little Johnny is in class. The teacher is going through the alphabet,
having each child think up a word that starts with a letter. They get
to "W", and the teacher figures Little Johnny can't think up anything
dirty with a "W" so she calls on him.
"Womb!", Little Johnny says.
"That's a good word, Johnny", teacher says. "Is that as in where babies
come from?" she asks.
"No", says Johnny, "That's the sound elephants make when they're
screwing... you know, "Womb! Womb! Womb!"