Rob and Laura are watching TV
Rob: Boy, the guy who put that on, he really has guts. That's Swan Lake isn't it?
Laura: The music's the same. The costumes are the same. After a while you forget they're monkeys.
We learn that Alan Brady's middle name is "Lester".
The title is taken from the 1949 movie A Letter to Three Wives directed by Joseph L. Mankiewicz.