The title is from a song from Rodgers and Hammerstein's 1951 musical The King and I starring Gertrude Lawrence and Yul Bryner. The original Broadway production opened at the St. James Theater on March 29, 1951, ran for 1246 performances, and won the 1952 Tony Award (New York City) for the Best Musical.
This episode, and season one's Father's Day, are the only episode of the series that take place during the Christmas season. Ironically both episodes aren't directly about Christmas but rather have completely non-Christmas related plots wherein the characters mention that Christmas is approaching.