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!

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 there, reading a magazines

"Hi darling", he says, "your parents have come to visit us, so I let them stay in our bedroom. Hope you have said hello to them.