This episode marks the first, but not the last, of Lou's marital woes coming in part because of his wife Edie's need for fulfillment and accomplishment in life, particularly as empty nest syndrome settles in.
Lou: (inviting Mary to dinner) We're having leftovers from [Edie's] Home Economics class.
Mary: That's OK, I love leftovers.
Lou: She got a C minus.
Lou: I look at a separation like two boxers who are going to their corners between rounds. That doesn't mean the fight is over, Mary. They're just resting!
This episode was filmed on January 08, 1971.