Same Time, Next Year
(1978)

Over the course of 26 years, Doris (Ellen Burstyn) and George (Alan Alda) develop a deep emotional intimacy despite the fact that both of them are happily married.

The last meeting occurs in 1977. George's wife Helen dies, though she had know about the affair for ten years but never told George.

George proposed to Helen even though she is still  married. They still plan on meeting as long as they are able.

Thanks Michael R!