I knew almost as soon as I started answering her seemingly innocuous but loaded questions that this would be the beginning and the end of our acquaintance. She glared across the table with undisguised contempt. "Oh really," she said. "Well, my father had an affair. It destroyed our family and I just think it's so totally wrong." The subtext was equally damning: "You sleazebag! A married man, trying to pick me up -- get real." We never spoke again.

Five years later, I was divorced and living in New York. "I hear you're the one who doesn't believe in monogamy," said one woman, out for drinks with me and a group of friends. "Tell us about it." I was already developing a reputation as the designated maverick. "It's not that I don't believe in monogamy," I explained. "It's that I don't think that monogamy is the only possible expression of human needs and desires."

"Sure," another friend replied. "That's just a convenient way of not committing to one person. And by the way, didn't you get divorced?"

Well, yes, I did. But not because my wife and I had affairs. I got married just out of college, when I was 21. At the time, marriage was the unconventional thing to do and that was appealing. Both of us liked to shock our friends, and telling them that we were getting married, moving to Europe and willing to have sex with others pushed all the buttons of envy and surprise.

When I first met my future ex-wife, she was dating two other men and I was involved with another woman. She didn't tell the other men she was seeing me, and I lied as well. Of course, it was college and rules were for adults. Still, the deception was nauseating and ultimately hollow. But the sex, oh my ... The excitement of sleeping with two women, the thrill of the illicit, the knowledge that she was as complicit as I was -- it all combined to create an erotic charge.

I realized that I wanted both an intimate relationship and no sexual boundaries. Some people like extreme sports, the adrenal thrill of challenging limits (and cheating death) by jumping off cliffs or skiing at 70-degree angles. I enjoyed extreme emotions. I wanted to venture into the unknown and non-monogamy was a frontier that few people wanted to traverse. I got married determined to explore.

It didn't exactly turn out that way.

For most of my marriage, non-monogamy was an idea to be probed at a later date. Then it finally happened. "I've been having an affair, with a doctor," my wife told me on the phone one day while I was away on a trip.

I was bewildered and angry, and of course I had no moral leg to stand on. I didn't mind the fact that she had had sex with someone else as much as I minded that, for her, the affair was a sign that it might be best to end the marriage. I tried to persuade her to stay, and for four years she did -- in body more than in spirit -- as we slowly consumed each other in anger and hurt.

Sexual experimentation remained part of the script that we shared with others in public, but like the couple who always talk about taking that trip to Fiji, we never did much to make it real. Both of us slept with a few other people in the remaining years of our marriage, but we didn't share our experiences with each other, we didn't delve into the feelings they brought up ("Did you enjoy it? Why?" "Does that threaten you?" "Why does sex with another man/woman make you think that I might leave?") and we didn't revel in our discoveries ("That turns me on ... Do that with me!"). Whenever we slept with someone else, we confessed, with neither guilt nor delight, and we went on.

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