A wife, in bed with her lover, heard her husband's key in the lock.
"Just stay where you are," she instructed, "he's always so drunk he won't even notice you."
Sure enough, the husband fell into bed none the wiser, but when he looked down and through his drunken haze saw six feet at the other end, he said, "What's going on here? There are six feet in this bed!"
"Nonsense," said the wife, calmly. "You're so drunk you can't count. Get out of bed and try again from over there."
So her husband staggered from the bed, walked to the foot of it and counted out loud, "One, two, three, four… damn it. You're right!"