Rosenmontag on AllMovie

Rosenmontag (U.S. title: Carnival's End) was based on the novel of the same name by Otto Erich Hartlebein. Thanks to ugly gossip, a young Army lieutenant is convinced that his sweetheart is an unfaithful trollop. He becomes engaged to another woman then marches off to war, having promised to forsake all other women. Eventually, he discovers that the stories about his first love were all lies. He returns to her and rekindles the romance, whereupon he remembers vowing eternal devotion to his present fiancee. Rather than sacrifice his honor, the lieutenant resorts to extreme and tragic measures to keep his promise.