What's It Called?

Little Johnny asked his mother, "Mommy, do you know what it's called when two people are sleeping in the same room and one is on top of the other?" Not wanting to lie to her son, she replied, "It's called sex, honey."

An hour later, Johnny came running back into the house and said, "It's not called sex, it's called bunk beds, and David's mom wants to talk to you."