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 newspaper.
"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.