Das weite Land (1969)

A promising young pianist commits suicide. He spent his last evening in the company of the industrialist Friedrich Hofreiter. His wife Genia is in possession of a farewell note, in which the pianist explains that she had refused to have an affair with him and that he had shot himself out of unrequited love. Genia's sacrifice and commitment to marital fidelity cause the notorious womanizer Hofreiter to hastily leave for the mountains, where he begins a new affair. During his absence, Genia embarks on an affair with Otto, the son of an acquaintance. When Hofreiter returns and finds out about his wife's adultery, he challenges Otto to a duel and kills him.