Like many others, I read Mark Oppenheimer's article on Dan Savage and monogamy in today's The New York Times Magazine (or online) with interest. I agree with the author and Savage that monogamy is not for everybody, and that people should not feel compelled to enter monogamous relationships if this is not truly what they want. I also agree with the idea that when forming a new relationship, the future partners should talk about the boundaries of their relationship, including what counts as adultery and if and when some straying outside the relationship will be allowed. Finally, I strongly agree that partners need to be honest with each other through the relationship, even when it's painful, and if both partners freely consent to change the nature of the relationship, that's their business.
What I think they overlook is the symbolic nature of fidelity. The sacrifices that partners make when they choose to enter into a monogamous relationship contribute to the meaningfulness of that relationship. Though my point applies to committed relationships in general, it bears mentioning that the traditional wedding vows mention "forsaking all others"—openly recognizing that the future partners may be tempted, and at the same time allowing them to show each other how much they are willing to give up to be with the other person and how much they mean to each other.
But when one partner strays, he or she breaks that agreement, saying in essence that the relationship (and the other person) doesn't mean enough to forsake all others anymore. The cheater has his or her reasons, good or bad, impulsive and deliberative, but that doesn't change the fact that the other person in the relationship was counting on the fidelity of his or her partner, valued his or her strength in face of temptation and took it as a sign of devotion and love. When one partner cheats, that shows the other that he or she wasn't worth that strength or resolve anymore—there are other things more important to his or her partner now.
This is where the authors are spot on with their call for honesty, particularly before any promises are broken. It simply shows respect for your partner to let him or her know that you have strong feelings, whether physical or emotional (or both), for another person, or that you have needs (again, whether physical, emotional, or both) that aren't being met in the present relationship. Being upfront with these feelings gives your partner the chance to try to satisfy them within the relationship. And if that can't be done, the relationship may be better off dissolved—maybe you aren't cut out for monogamy—or, perhaps, you will see that you value the other person, and your relationship with him or her, more than your unmet needs. In the best case scenario, urges to stray can be useful as a sign that something needs tending to in the relationship, rather than as an excuse for playing around.
A question to end with: Why is it so hard to expect people to give up things for the people they love? Why is it that in this day and age, when we are urged to sacrifice time, money, and comfort for the sake of the environment or political causes—commitments well worth making and sacrificing for—we are not urged to make similar sacrifices to the persons we have pledged fidelity to? Why are we so hard on ourselves in some areas and not others?