Few things put as much strain on a marriage as an affair. When we see affairs exposed in very public ways, played out in the news involving politicians, celebrities and athletes, we all cringe and say "that will never happen to me." In reality, it happens to a lot of couples: rich or poor, beautiful or not. Infidelity is an equal opportunity marriage buster.

Finding the Seed of the Affair
When couples struggling with an affair come to me, I tell them no matter what the circumstances, an affair never happens out of the blue. It’s actually an extreme symptom of a marriage that’s been in trouble for some time. I also tell them an affair is a powerful catalyst that can either end their relationship or take it to a greater level of intimacy.

Even an affair that seems starkly one-sided isn’t. It always takes two to dance the dance of a relationship and to create unresolved issues. Though to some, this may sound almost blasphemous, but the truth is every affair has two victims. When the issues come out in the open, the couple has a chance to stop the "victim" cycle, and each person can begin to take responsibility for their own wounds.

I’ve found that the best way to get to the heart of a couple’s issues is to ask them about their first argument as a couple. Usually, there’s stunned silence and puzzled looks. For them the affair is the only relevant issue. It’s as though a fire has burned all the oxygen and left them no breath for talking about anything else. But I find, that in almost all cases, in that first argument, they’ll find the root of their struggles as a couple and the seed of the affair.

To Stay or Go
Why do some marriages not only survive, but actually grow in the wake of an affair? Couples who make it through are determined to look at themselves and not just to cast blame on their spouse. They recognize that the affair arose as a symptom of long-standing problems between the two of them. They have a strong desire to make their relationship work. They understand that the work will not be quick and easy and they adopt a realistic time frame. Deep down, they know they have a genuine love for one another.

If both partners sincerely work on the relationship, glimmers of hope will spring up all along. For most people, however, it seems to take at least a year to move through the full cycle of renewal.

When couples don’t stay together, it has less to do with the particular circumstances of the affair than with the couple’s long-term history and with their willingness and ability to explore it. Sometimes it seems the reservoir of resentment and hostility is just too overwhelming, and that so much damage has been done that there is little left to salvage.

When one partner cannot or will not do anything to change damaging behavior, then the only solution may be for the other partner to leave. To stay in a marriage—in which one continues to be hurt—reflects a belief that one deserves no better. It’s not a failure or a sign of weakness to leave a destructive relationship. Rather, it’s a sign of success and strength in oneself and heightened self-esteem.

There is no "right" way to deal with an affair: some couples stay together, some couples separate. No matter what the eventual outcome, an affair challenges both partners to look at themselves and their relationship in a radically new way.

A licensed therapist for over 28 years, Sharon M. Rivkin, MA, MFT, is the author of "The First Argument: Cutting to the Root of Intimate Conflict" and developer of the "First Argument Technique," a groundbreaking method that heals and saves relationships. For more info go to www.sharonrivkin.com.