The Last Married Couple in America (1980)

Director: Gilbert Cates
Cast: Bob Dishy, Dom DeLuise, George Segal, Marilyn Sokol, Natalie Wood, Priscilla Barnes, Richard Benjamin, Valerie Harper

Synopsis:

Jeff and Mari Thompson are contently married, but they are stunned to see many of their friends and neighbors going through separations and divorces. Seemingly surrounded by people with domestic problems, Jeff and Mari begin to question their own relationship.