The character of Norman is played by Tom Poston. For the last six years of his life he was married to Suzanne Pleshette, who played Karen's mother.
Tom Poston and Suzanne Pleshette (who appeared as Karen's mother in a couple of episodes just before this one) co-starred in the popular sitcom The Bob Newhart Show (1972). Pleshette played Bob's wife throughout the series. Poston played their friend/neighbor. They were married to other people at the time.
The title is a play on lyrics in "Garden Party," a 1972 pop song hit by Ricky Nelson. The song begins "Went to a garden party..." Nelson, a popular actor and singer for over 30 years, died in a plane crash Dec. 31, 1985.