Lady of the Pavements (1929)

Karl, a German diplomat in Paris, discovers that his fiancée, Diane, has been unfaithful. He tells her that he would rather marry a 'girl of the streets' than her. Outraged, Diane enlists the services of a Spanish singer/dancer from a disreputable nightclub to pose as a sophisticated, convent-educated singer, and surreptitiously arranges for her to meet Karl.