At Friday night services, Morris goes to his friend Irving and says, "I need a favor. I'm sleeping with the Rabbi's wife. Can you hold him in the synagogue for an hour after services for me?"
Irving is not very fond of the idea, but being Morris' is his very best lifelong friend, he reluctantly agrees.
After services, he strikes up a conversation with the Rabbi, asking him all sorts of stupid questions - just to keep him occupied.
Irving, filled with feelings of guilt and remorse confesses to the Rabbi, "I'm sorry, Rabbi. My friend is sleeping with your wife right now, so he asked me to keep you occupied."
The Rabbi smiles, puts a brotherly hand on Irving's shoulder and says, "You better hurry home, Irving. My wife died two years ago!"