A wife comes home late at night and quietly opens the door to her bedroom. From under the blanket she sees four legs instead of two, so she reaches for a baseball bat and starts hitting the blanket as hard as she can. Once she's done, she goes to the kitchen to have a drink.
As she enters, she sees her husband sitting there reading a magazine.
“Hi Darling”, he says, “your parents have come to visit us, so I let them stay in our bedroom. Have you been in to say hello?”