The Smiling Lieutenant (1931)

A simple wink, intended by Austrian palace guard Lt. Nikolaus von Preyn (Maurice Chevalier) for girlfriend, Franzi (Claudette Colbert), is accidentally intercepted -- and misread -- by the visiting Princess Anna (Miriam Hopkins). As a result, the soldier has no choice but to marry the royal lady and move with her to the neighboring kingdom of Flausenthurm. His girlfriend follows to continue the romance and, subversively, give Princess Anna tips on how to keep her husband satisfied.