The Truth About Youth (1930)

Richard Carewe has raised his deceased friend's son from childhood with the help of his housekeeper and her beautiful daughter Phyllis. He arranges a marriage between the lad and Phyllis, but the rascal impulsively marries a notorious nightclub singer known as "The Firefly." The femme fatale dumps the boy when she discovers that he has no money, but by then Phyllis realizes that she is in love with Richard, not his foolish ward.