The desire to find happy endings for sad human stories is probably lodged in most couples therapists' DNA. When the "sad story" is about infidelity that threatens a marriage, therapists generally aim for their favored resolution: saving the marriage. As a field, we've tended to think about this story in terms of a straightforward, three-part narrative: Part 1: A couple is shattered by the discovery of an affair and comes to see us. Part 2: We help them get through the immediate crisis, tend to the underlying wounds in the marriage, and then take a deeper look at childhood scars. We provide compassion and advice as needed, and encourage new trust, forgiveness, and intimacy in the relationship. Part 3: As our preferred denouement, the couple leaves therapy weeks or months later, their marriage repaired, stronger, even transformed—or at least improved. We consider treatment a success; the couple has weathered the storm. Of course, some couples refuse this neat storyline and, instead, use therapy as a gateway out of the marriage altogether. But, hopefully, they still live happily ever after.

However, we typically have no idea what really happens "ever after." Helping couples recover from the immediate crisis is critical, but what happens to them after they leave therapy? Did the insights gleaned carry the couple through the years of marriage, the slings and arrows of ordinary domestic fortune? Was there a brief, second honeymoon before the marriage…