Carola (1973)

During World War II, an acting company in occupied Paris is notified that a German officer will be stopping by to see their play. The stage manager--who also happens to be the lover of Carola, the lead actress--asks her to "play up" to the visiting German for the good of the play, but when the officer arrives, it becomes clear to the manager that the German and Carola have had a previous relationship, and that she is still in love with him.