When my former boyfriend discovered that I had cheated on him, I felt physically sick with guilt, despair, and grief. But I also had plenty of excuses as to why I did it.

After I moved thousands of miles away for a job, we struggled to adjust to a long-distance relationship. I felt neglected, lonely, and unable to communicate what I needed via Skype. When I met someone new and exciting, I told myself we were just friends. And then we weren’t.

During our first visit in nearly a year, I forgot to log out of my Facebook on my partner’s laptop. He read my messages, and the life we’d built together exploded. Of course, it was all my fault—I’d planted the bomb and somehow hoped he’d never find it. Many painful, hours-long conversations followed, as did an attempt at an open relationship. But we couldn’t recover.

A few years later, I got a taste of my own medicine when a new partner cheated on me. I completely lost it, and despite my need to ask how he could hurt me like that over and over again, none of his explanations mattered. In my mind, he was bad, cheating was bad, and it was that simple. Pretty hypocritical, right? Unfortunately, I’m not alone.

Cheating can destroy a marriage, shatter your ability to trust future partners, hurt your kids, and even lead to depression, anxiety, and post-traumatic stress disorder (PTSD). The vast majority of adults agree that it’s wrong, but anywhere from 39 to 52% of us may experience infidelity at some point in our lives.

Why do people cheat?

“There’s a multitude of reasons why people cheat,” says Kenneth Paul Rosenberg, M.D., a psychiatrist and author of Infidelity: Why Men and Women Cheat. According to a 2017 article published in the Journal of Sex Research, explanations for infidelity often dip into three main categories: personal problems, beliefs, or characteristics; issues with your partner or the relationship as a whole; and situational factors like easy access to dating websites, long business trips, or liquid courage.

To further complicate things, sometimes what “counts” as cheating to you may be radically different from what your partner sees as okay versus definitely not okay. Research shows our definitions of infidelity can range vastly from having a celebrity crush or watching porn on the conservative side to only in-person sex acts on the more liberal side.

Although sexual relationships are often considered the worst of betrayals, Dr. Rosenberg says it’s important not to underrate emotional affairs, which can be just as devastating.

If you’re here, you’re probably trying to understand why you, your partner, or someone you care about cheated. There may be no single reason why, and it’s often difficult to get a satisfying answer out of someone who has mastered the habit of lying to you or feels deeply ashamed and confused.

But to give you some insight, we asked real people to explain why they cheated—and asked relationship experts to weigh in on the reasoning, plus how you can begin to sort out what comes next after infidelity.

1. The relationship wasn’t fulfilling anymore.

I cheated because I was really dissatisfied with our relationship and didn’t feel seen or understood by my partner. I confessed immediately afterwards, and today, my ex remains one of my oldest friends. Looking back, I wish I’d had the emotional intelligence at the time to tell him how I felt or break up with him. —Taylor C., 23*

One common reason for cheating is that the partnership isn’t satisfying, says Ashley E. Thompson, Ph.D., an associate psychology professor who researches infidelity at the University of Minnesota in Duluth. If you’ve grown distant, don’t have anything to talk about, or can’t remember the last time you had sex, you or your partner may end up looking for connections outside of the relationship rather than trying to fix problems at home.

2. They didn’t think through the consequences.

I cheated out of stupidity. I was just on autopilot. I was hanging out with someone, they seemed receptive, and I went for it. I wasn’t really letting the potential consequences of my actions rise to consciousness. I was simply doing what felt good in the moment. Many years later, I feel like I’ve grown out of it. Falling in love with the right person certainly helped. —Jackson P., 45*

The saying, “Once a cheater, always a cheater,” by no means applies to infidels across the board, but it might have a grain of truth, says Thompson. “There are certain personality characteristics that are indicative of folks who commit infidelity,” she says. In particular, people who are not so self-disciplined may be more apt to say they were “swept away by the moment” due to factors like mood lighting at the bar or too much to drink when, in fact, their own impulsiveness and penchant for risk-taking could be to blame.

3. They got a rush out of it.

I cheated on my first wife because I got off on the intrigue—the planning, excitement, my so-called brilliance at not getting caught. My second wife is a real partner in every sense of the word, and I haven’t thought about straying in 15 years. When you cheat on someone, whether you get away with it or not, you create a wound in your partnership that doesn’t entirely heal. Enough of those wounds or a big enough one, and you kill your relationship. That’s what keeps me honest today—the sense that you can “win” and still wind up the loser. —Ian G., 45

“A fair number of people cheat just because they can,” says Dr. Rosenberg. Contrary to the stories you often hear about discontent spouses, a partner who cheats might be relatively happy with their primary relationship but their partner isn’t open to a non-monogamous arrangement, they want the best of both worlds, or they get a thrill from secretly pursuing new hookups.

On a biological level, people who are more prone to infidelity may be driven by an upsurge in pleasure chemicals like dopamine, vasopressin, and oxytocin. Those who are more extroverted may be more likely to cheat because they thrive on new social connections.

4. They suffered from low self-esteem.

I cheated because I wanted validation. I was very insecure and had to be the center of my partner’s attention all the time. I didn’t feel happy or worthy if I wasn’t constantly being fawned over by him. The night it happened, I was at a party, someone else started flirting with me, and it went downhill from there. Since then, I’ve vowed to never hurt someone like that again and I’ve learned not to look for an external source to solve an internal problem. I still struggle with low self-esteem, but that’s my problem, not my partner’s, and I know that cheating won’t “fix” it in any way. —Alyssa G., 29

Often, there are conscious reasons for cheating (like: “You don’t give me enough attention!”) as well as more unconscious reasons (such as problems dealing with difficult emotions or trauma), says Gilza Fort Martínez, a Miami-based licensed family and marriage therapist specializing in life transitions and conflict resolution. Over half of people who cheat say self-esteem has something to do with it.

If a partner isn’t feeling good about themselves and isn’t addressing that in a healthy, productive way, such as therapy, they’re more likely to end up in a relationship wracked with negativity and fighting. As a result, they might seek out someone else to boost their shaky ego or establish a sense of control over their lives—even if it’s ultimately self-destructive.

5. They craved sexual variety.

I knew cheating wasn’t right, but I couldn’t find the willpower to stop myself. While I think I’d be capable of monogamy now, I choose to be polyamorous because it allows for more boundary-setting, communication, and the ability to talk about desires and sex without worrying about jealousy. This way, I can keep myself relatively independent while still enjoying people’s company. —Ami M., 23

It’s normal to find other people attractive, have sexual fantasies, or want multiple sexual and/or romantic partners in your life. But when you act on those desires without your partner’s knowledge and enthusiastic consent, you get into tricky territory.

Some people tend to be more open to sex outside of their primary relationship and could end up cheating if they don’t communicate their needs to their partner. A better alternative? Just be honest with yourself and your partner about what you want, says Dr. Rosenberg. These days, you do have options like ethical non-monogamy, polyamory, or an open relationship.

6. They wanted revenge.

In college, I was dating this terrible guy and planned to break up with him. However, I decided to be spiteful and ended up sleeping with a friend of mine who I ran into randomly while running errands. When we reconnected, I began to think about all the horrible things my boyfriend had said to me, the put-downs, lack of appreciation, drama. I just didn’t care anymore. I know it was immature, wanting revenge like that. I’m not proud of it. But I also don’t feel like it was that big of a deal compared to what he put me through. —Vanessa R., 38

If you’ve ever been betrayed by a partner, you know that fury often comes along with anguish and confusion. The desire for revenge is another common motive for infidelity, says Thompson. While many cheaters will do everything they can to avoid getting caught, others might want their partner to find out in order to “get back at them” for having an affair or treating them poorly. Case in point: Nearly half of people who cheat say anger factored into their reasoning, according to one study.

7. The relationship wasn’t healthy.

I was in a bad marriage with an abusive man, and one of the few things he allowed me to do was go to karaoke with friends. One night, I met a guy who was funny and so unlike my husband. Hanging out with him—and eventually cheating with him—gave me confidence and made me realize how I actually deserved to be treated. I know there’s no excuse for infidelity, but to me, the real story is I found someone who really cares about me and gave me the guts to get a divorce. Over four years later, we’re still together. —Liz K., 29

While there’s little research on this, some study participants’ stories suggest infidelity could actually serve as “an adaptive mechanism by which to escape” for someone in a toxic or abusive relationship, says Thompson.

If you’re unable to end a bad relationship or want to but can’t quite take that step yet, having an affair with someone else who treats you well could serve as a reminder that you’re entitled to a healthy, happy, and fulfilling relationship—and give you the courage to get out, confirms Tammy Nelson, Ph.D., a sexologist, licensed relationship therapist, and author of When You’re the One Who Cheats.

If you’ve been walking on eggshells or feel unsafe with your partner, you can figure out next steps with the help of a therapist or a resource like the National Domestic Violence Hotline (NDVH) at 1-800-799-SAFE (7233) or TTY 1-800-787-3224.

8. They weren’t in love anymore.

Many years ago, I was married to someone I got along with great, but our sex life was never passionate. I had this friend who I’d always genuinely enjoyed being around, and felt this sexual tension with. One night, we finally opened up about how we felt and had this incredibly passionate kiss. I felt like I’d finally woken up after years of just going through the motions. I was ashamed that I’d let my life go so far and felt guilty for wasting my wife’s time, too. I told her everything and we got divorced. Today, I’ve been married to this new person for over 20 years, and my ex is happily single. Cheating is wrong and it destroys people and marriages, but living a life without passion is just as wrong and also destroys people. —Chris B., 47

Of all the reasons for cheating, the most painful and common one is simply a lack of love. At the beginning of a relationship, just grazing your partner’s hand can get your heart thumping, let alone seeing their clothes come off. “But that kind of romantic love lasts a couple of years—if you’re lucky,” says Dr. Rosenberg. Because we’re “passion-bound creatures,” fidelity isn’t always easy when that initial spark fades, he says.

“Just because you’re married doesn’t mean you’re immune to falling in love with another person,” adds Nelson. Sometimes, as heartbreaking as it can be, relationships have expiration dates. While it’s best to end a partnership with integrity before moving on, when someone begins to feel the heat with another person, they may cheat before they can admit that their initial partnership has truly fizzled out.

How to recover from infidelity

Whether you cheated or your partner betrayed you, the first step is to find a trusted loved one, mentor, or therapist to talk it out with individually, says Dr. Rosenberg.

The next stage is to ask yourself some hard questions: Are you staying or are you going? What are the pros and cons of each option in terms of the effect on your family, financial entanglements, the history you share? What was your relationship like before the betrayal and how might you rebuild trust? Both partners have to answer these questions on their own, says Fort-Martínez.

“Cheating is a painful, often very devastating situation, but it could also be a gift.”

After that, if you choose to stay together, a couples’ therapist can help you navigate the grieving process, work on your communication skills, regain intimacy, and move forward. To make it work, Fort-Martínez says she looks out for three key things in the person who cheated: the willingness to be open and transparent, the ability to take emotional hits from a distraught partner, and expressions of true remorse.

If you decide to break up or get a divorce, know that there’s no foolproof way to prevent infidelity in the future, but you can do your best to lower your risk. To avoid misunderstandings, all of the experts we spoke with recommend that you have an honest conversation about what exclusivity means to you and make compromises on boundaries and expectations so you’re on the same page from the very beginning.

“Cheating is a painful, often very devastating situation, but it could also be a gift,” says Fort-Martínez. You may finally realize your relationship has been broken for a long time, you’re free at last, or you haven’t been valuing your connection—and it’s time to pay more attention to yourself or your partner.

*Name has been changed

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Lauren Krouse
Lauren Krouse is a freelance writer who covers health, domestic violence, and self-advocacy. Her work appears in _Women’s Health, Men’s Health, Prevention, Self, HuffPost, and elsewhere. When she’s not writing, you can find her trying to meditate more, weightlifting, or walking in the woods with her partner and black lab.