When Lucy questions who the flowers are from, she asks, "Fred who?", to which Ethel replies, "You know Fred who!" Lucy says, "Oh, now, Ethel. You certainly don't think these are from Fred Mertz, do you?" Ethel replies, "Well this card certainly wasn't written by Fred MacMurray!". William Frawley (Fred Mertz) and Fred MacMurray later appeared in 165 episodes of My Three Sons (1960) together, from 1960-1965.