The title is from a line that Ann says to Don when Don's mother discovers Don's pants in Ann's closet: "Oh Don, Poor Don, Your Pants Are Hanging in My Closet and I'm Feeling So Sad."
The title of this episode (abbreviation of: "Oh Donald, Poor Donald, Your Pants Are Hanging In My Closet And I'm Feeling So Sad" ) is a takeoff of the 1962 Off-Broadway black comedy "Oh Dad, Poor Dad, Mamma's Hung You in the Closet and I'm Feelin' So Sad " which was also made into a film "Oh Dad, Poor Dad, Mamma's Hung You in the Closet and I'm Feelin' So Sad (1967)" in 1967. The film starred Barbara Harris (who also appeared in the play), Jonathan Winters, Rosalind Russell and Robert Morse.
Mrs. Hollinger tells Ann that "a son is a son till he takes him a wife, but his mother is his mother all of his life." Her sentiment is a very loose adaptation of the quotation found in the English naturalist John Ray's compendium of quotations from 1670: "My son's my son 'till he hath got him a wife, but my daughter's my daughter all days of her life." Spencer Tracy's character uses the line in Father of the Bride (1950) that more closely aligns with John Ray's quotation when he shares the sentiment with Elizabeth Taylor's character.