Roger Ebert sez:
The Segal character has a loving wife and kids at home, a loving mistress in the city, a manager who wants him to make lots of money, and a harassed conscience. His basic problem is that he wants to do the right thing by everybody, and can’t. How can you do the right thing by your mistress when, just by having a mistress, you’re doing the wrong thing by your wife? And vice versa, these days.
So Segal sinks into the confusions of suburban morality, substituting the martini lunch for the confessional. He can afford ethical soul-searching better than his wife, Eva Marie Saint, who gets to wrestle with the kids while he’s wrestling with his conscience. That’s part of the problem, too, even if Segal gets everything straightened out morally, his marriage may expire from exhaustion.