Her Third (1972)

Original title: Der Dritte

In this East German film, the third one in The Third is Margit's third lover. After her mother's death, Margit has two affairs which don't work out, and one lesbian friendship which she retains. She is looking for a husband, though, and thinks she has spotted a candidate in her fellow factory worker. As she contemplates marrying him, her story is told in a series of flashbacks.