My Head, Your Wife
A middle-aged executive was becoming increasingly irritated by the constant ribbing he was taking from the junior employees who couldn't resist making fun of his baldness. One morning, a particularly brash trainee had the gall to run his hand across the older man's gleaming head while loudly exclaiming, "Feels just like my wife's ass."
With a look of genuine curiosity, the aging exec rubbed his hand across his head. "You're right," he said, "it does!"