Question: "But It's Better If You Do" is a song whose title is a quote from a U.S. melodrama film written by who?
Sentence (from "Caminito de Gloria"): The film starred Libertad Lamarque, who sings "Caminito", the celebrated 1926 tango composed by Juan de Dios Filiberto with lyrics by Coria Peñaloza originally popularized by Carlos Gardel and Ignacio Corsini.
Relevant evidence: No