The Best Kind of Housekeeping

One day Stan comes home from a hard day at work. He sees his wife bending down to clean the floor under the sofa. So Stan goes over to his wife and starts fucking her from behind. After he finishes, he gives her a hard smack to the head.
His wife yells, ''What was that for!?''
To which Stan replies, ''That's for not checking to see who it was.''