Lovers and Other Strangers is a 1970 comedy film based on the play by Renée Taylor and Joseph Bologna. The cast includes Richard Castellano, Gig Young, Cloris Leachman, Anne Jackson, Beatrice Arthur, Bonnie Bedelia, Michael Brandon, Harry Guardino, Anne Meara, Bob Dishy, Marian Hailey, Joseph Hindy, and, in her film debut, Diane Keaton. Sylvester Stallone was an extra in this movie. The film was nominated for three Academy Awards (it won the Academy Award for Best Original Song), and was one of the top box office performers of 1970. It established Richard Castellano as a star (receiving an Oscar nomination for his performance) and he, along with Diane Keaton, was subsequently cast in The Godfather. The song For All We Know was composed by Fred Karlin with lyrics by Robb Royer and Jimmy Griffin. Wikipedia
Richie Vecchio: Don't you understand, Joan and I are just not happy together.
Frank Vecchio: You hear that, Beatrice? They're not happy together.
Bea: I heard, Frank.
Frank Vecchio: So who's happy?
Bea: Who's happy?
Frank Vecchio: What, do you see me running around dancing in the streets?
Bea: Do you see your father running around dancing in the streets?
Frank Vecchio: What are you, better than me? You think your mother and I are happy?
Richie Vecchio: You mean you and mom aren't happy?
Frank Vecchio: (together with Bea) No!
Richie Vecchio: Then why did you stay together?
Frank Vecchio: (pause) We're content.
Bea: We're content.
Frank Vecchio: These kids today, all they're looking for is happiness.
Bea: Don't look for happiness, Richie. It will only make you miserable.