Rick was my first real boyfriend, my high school sweetheart, my date to four proms. He was the first guy I'd ever brought home who could look my mom in the eye. A nice guy. A year after Rick and I first started dating, I came home from high school one day and my father was gone. Just like that, he'd left my mother for another woman. I never dealt with the abandonment. Instead, I consoled myself with the knowledge that Rick loved me and would never leave me, not like my dad had. Never mind that he and I grew less compatible as we got older—he was everything my father wasn't.

The first time I cheated on Rick, we were freshman in college and I was living in Mexico as a student abroad. I slept with a guy who worked behind the deli counter of the bodega on the street where I lived. I told myself, What happens in Mexico, stays in Mexico. I told myself it didn't count.

Then it happened again, this time back on campus. One night I drunkenly stumbled home with a guy I'd met at a party. I told myself it'd been a mistake. I kept dating Rick. I never told him and he never found out.

I told myself it didn't count. Then it happened again.

A lot of people think monogamy simply doesn't work. They argue that human beings just aren't wired to be with one person and one person only—a common argument that was used in defense of the people outed in the Ashley Madison hack—and that it's time to do away with this convention. This was how I justified my transgressions back then, by telling myself I couldn't control it. It was just human nature.

I didn't stop.

My first full-blown affair happened a few years later, after Rick and I had graduated college. This time was different. Brie and I had been friends first. We trusted and respected one another. That didn't change when we started having sex. I thought I was in love with her, and so I came clean and told Rick I was having an affair.

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I thought that telling him about Brie would absolve me of the guilt I felt for all my past indiscretions, but that didn't happen. Rick was devastated; it was all my fault. To Rick's credit, the fact that it was a woman made it neither better nor worse. He wanted to work it out, and I felt I had no choice. I was confused, we decided. I convinced myself that Brie had taken advantage of me and that it had been a mistake.

After my affair with Brie, I redoubled my efforts to gain control of the situation: I tried to be "good." I stopped drinking and started running marathons. I quit my job and went back to grad school to become a writer. Two years later, Rick and I were engaged.

But in grad school, I met a new group of people. They thought like me and read the books that interested me. We talked about sexual liberation. I considered myself sex-positive, part of a social movement that embraced sexuality with few limits. The problem was that—when it came to sex—these political and intellectual beliefs about sex made it that much harder to admit that my personal sexual conduct was problematic.

I'm just incapable of monogamy, I was still convinced. Since Rick wanted to be with me, this was something he'd just have to accept.

Justin was a guy I met in grad school. He and I would chat online all day when I was at work, and we started attending literary readings together in the evenings. We were seen together so often people started to assume we were dating. Secretly, I enjoyed this. Never mind that I was still engaged to Rick at the time. Justin was a writer, destined for success, popular in the way that tenacious, overachieving kids can be. Though my relationship with Justin had yet to turn sexual, it felt inevitable.

One night during this time, a guy named Elliott walked me home after class. Whatever we talked about was not interesting, but I could tell that Elliott was interested in me and I liked the feeling of being desired. Under the pretense of having something to do with school, we started exchanging emails daily. Justin and Elliott were friends, and I kept my relationship with one from the other (and both, obviously, from Rick).

any chance I got, I'd get drunk and fall into my classmates mouths—forgettable, regrettable, sloppy encounters in the restrooms, stairwells, and alleyways.

The impossibility of my actually being with either of them made it all the more exciting. Elliott suggested once that I shouldn't flirt with him because I had a fiancé. Hearing "no" only egged me on. I admired his resistance.

Then, once while drunk, I leaned into Justin and kissed him. He kissed me back. I immediately regretted it, knowing exactly what would happen. I knew I'd become insecure and possessive. Like my relationship with Brie, my friendship with Justin would be destroyed. It was as if the only way I knew how to handle having done something I regretted was to do it again. That kiss led to a short-lived affair with Justin, which lead to a series of other infidelities. For the next month, any chance I got, I'd get drunk and fall into my classmates mouths—forgettable, regrettable, sloppy encounters in the restrooms, stairwells, and alleyways.

I told myself I was having fun, experimenting. But it was more than harmless fun. I pretended Rick and I had an open relationship. I convinced myself that our rule was "Don't ask, don't tell."At the same time, I resented Rick for not calling me out. I lost respect for him. I also lost respect for people who fooled around with me. I lost respect for myself.

Ultimately, carrying on multiple relationships was a complicated way of avoiding intimacy. I clung to Rick, even though it was an ill fit. Because he didn't satisfy my impossible neediness, I cheated. I was never fully present in any one relationship, and thus avoided being vulnerable. Underneath it all, my actions were motivated by the fear I was unlovable and that I would be abandoned. The worse I felt, the more I sought relief.

When I finally left Rick, I took everything: the furniture, the posters from the walls, photographs ripped from the albums. I came by the night after I moved out and found Rick crying, alone, sitting on the floor. The look on his face was as if I had died, and so I felt afraid. I said, "Stop crying or I'll leave."

"You're leaving anyway," he said. "There's nothing I can do to stop you."

He was right. There was nothing that he or anyone could have done to stop me. I was a monster, abandoning someone who loved me. I was just like my father.

It took me a long time to recover, whereas Rick started dating someone else less than a month after we'd broken up—the woman he would eventually marry. Around the time they started dating, Elliott stopped returning my emails. He was doing me a favor by cutting me off, but of course I didn't see it that way then. When Elliott refused to step in and rescue me, I grew increasingly desperate. I felt abandoned. I was angry at my friends. Recovery began when I finally started taking responsibility for my actions: I went to rehab for my alcoholism, and my addiction to sex and love.

I didn't do recovery perfectly. They tell you to take time away from dating, but I couldn't do that. My sixth day of sobriety, I fell into a codependent relationship that lasted for six years. It was dysfunctional, but at least I was monogamous. When that relationship ended, I dated lots of people. But eventually I did go cold-turkey single for around three months, and it was one of the most transforming periods of my life. I learned to enjoy my own company. I grieved the loss of my father and became acquainted with the feelings I was running from .

Today I know that while non-monogamy may be human nature, cheating is not. Everyone is capable of being honest about their feelings, wants, and needs. Before this, I blamed everyone for my cheating and had loads of excuses, but when it comes to infidelity, I don't think there's ever an excuse. The fact that I'm in a committed, monogamous relationship today is almost beside the point. To be right in a relationship, I needed to get right with myself.

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