A man returns home from work and enters through the kitchen door. He sees his wife on her hands and knees scrubbing the floor. She only has an apron on so the husband gets a big hard on and starts humping his wife doggy style. When he is through he pulls out and at the same time hits her real hard upside her head.

"What was that?" the wife screamed "Here I am being so nice to you, and letting you really enjoy yourself. What did you hit me for??"

The husband looks at her and angrily says "For not looking back to see who it is"