At Friday night services, Morris went to his friend Irving and said, "Irving, I need a favor - I'm sleeping with the rabbi's wife. Can you hold him in temple for an hour after services for me?"
Irving not very fond of the idea, but being Morris' lifelong friend, he reluctantly agreed.
After services, he struck up a conversation with the rabbi asking him all sorts of stupid questions in an effort to keep him occupied.
After some time, the wise rabbi became suspicious and asked, "Irving what are you really up to with all this?"
Irving, filled with feelings of guilt and remorse, confessed to the rabbi "I'm sorry Rabbi, my friend Morris is sleeping with your wife right now and asked me to keep you occupied."
The wise rabbi smiled and, putting a brotherly hand on Irving's shoulder, said "Irving I think you'd better hurry home, my wife died two years ago!"