Once A Cheater, Always A Cheater…Or Not? Here’s What The Science Says

Things are going remarkably well with our new boyfriend; he’s funny, sweet, charming, dependable, and always plans the best dates. We get along famously and can’t imagine what would ever make us want to break up with him – that is, until we find out something about his past: he’s cheated before.

This new revelation can feel like a punch in the gut. We can’t remember a time when we hadn’t heard the phrase, “Once a cheater, always a cheater,” making us wonder if we can really trust him to be faithful. If he’s done something so awful to someone else he supposedly cared about, what makes us think the same thing won’t happen to us?

So are we right for wondering these things? Is there any merit to the idea of “once a cheater, always a cheater”?

The Answer Is Both Yes and No

It’s tempting to either totally prove or disprove this idea, depending on whether we hope our relationship will work, or we’re looking for an out. But unfortunately for us, the science doesn’t land firmly on either side.

While serial cheaters do exist, and studies have found that someone who’s cheated in a past relationship is more likely to cheat again than someone who never has, this also doesn’t mean that someone who had an affair once will definitely do it again. There’s more to take into account when trying to predict whether or not someone will cheat: their motivations, the circumstances that led to cheating, personality, etc.

Someone who has cheated is more likely to cheat again than a non-cheater, but it’s not inevitable.

This may make us even more on edge. If we could at least know for a fact he’d cheat on us one day, we’d just end things before that could happen. But we don’t know this for sure – making how our boyfriend behaves presently, rather than how they have in the past, all the more important to observe.

How Can We Tell If He’ll Cheat Again?

Having cheated in a prior relationship is a red flag that shouldn’t be ignored or explained away. We can’t just assume that he’d never do the same thing to us or allow the blame to fall entirely on his ex. It doesn’t matter if we couldn’t be more different than the girl he cheated on. What truly matters in this scenario is whether or not he’s different.

The key differences between a serial cheater and someone who has cheated is how they feel about their cheating, how much responsibility they take, and if they’re willing to be honest about how terrible and wrong their decision to be unfaithful was.

A guy who’s bound to cheat again will make his repeated infidelity the faults of exes, show little remorse for his past actions, lie about other things, and be overly secretive and protective of his phone. He might say in passing that he feels bad about cheating, but we’ll get the sense that he doesn’t feel shame.

But a guy who won’t cheat on us will be open and authentic about his past infidelity, acknowledge why we’d hesitate to trust him, express genuine regret, assume responsibility for the choices he made, admit that his ex didn’t deserve that (even if she wasn’t perfect), explore what made him cheat (if he’s in therapy, that’s even better), and articulate that he never wants to make that mistake again. He’ll feel a healthy guilt over his decision and take real steps that will keep him from hurting someone else this way.

Is It Smart To Stay If He Cheated on Us?

But what if we aren’t wondering if he’ll cheat on us one day? What if he already did? Should we give him another chance? We’ve invested so much in the relationship already, genuinely love him, and just want things to get back to the way they were. But we still have a nagging feeling that we’re making a huge mistake by taking him back – and we don’t want to be made the fool again.

What truly matters in this scenario is whether or not he has changed.

It’s a difficult question to answer because no two relationships and situations are the same. What’s likely true in every relationship, however, is that the trust between us will be totally gone – and without trust, it’s impossible to have a healthy relationship.

Whether or not we stay with someone who was unfaithful is a personal choice. Some of us have a no-cheating policy and will end things after infidelity has occurred, no exceptions (which is completely understandable). Others wonder if they can make things work, despite this wound. But if we choose to stay, it’s imperative that we’re making that decision carefully, wisely, and rationally, not emotionally.

The truth is that our boyfriend (or even worse, our husband) violated our trust and disrespected us with their actions. It’s important that they show the signs of someone who won’t cheat again, are willing to work with us in order to rebuild the trust that’s been broken, and that we’re honest with ourselves about our ability/desire to work past this betrayal. In many cases, getting professional help from a couple’s counselor will prove to be helpful as we find our way forward.

Closing Thoughts

The bottom line? Once a cheater doesn't necessarily mean always a cheater. But there are signs we have to pay attention to that will help us evaluate whether or not our boyfriend or husband will make their infidelity a pattern.

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