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Mumsnet has not checked the qualifications of anyone posting here. If you need help urgently or expert advice, please see our domestic violence webguide and/or relationships webguide. Many Mumsnetters experiencing domestic abuse have found this thread helpful: Listen up, everybody

Do you believe "once a cheater, always a cheater"

176 replies

worldshottestmom · 25/03/2026 20:07

I just want to preface this before anyone jumps on me:

  1. I’ve never cheated and never would.
  2. I think it’s awful and I’m not trying to defend it at all.

Just interested in a general discussion really.

So, long story short one of my friends has been seeing a man for a couple of months and it’s starting to get a bit more serious. She thinks he’s great and can see it going somewhere, but her one hesitation is that he told her he cheated on his ex when he was 22. He’s now 31 (she’s 29).

it got us talking about the whole “once a cheater, always a cheater” thing. I’m a bit on the fence with it. I do think for some people it’s just who they are; no real morals, low self-esteem, impulsive, etc, and they’ll always cheat regardless.

But I also think there are cases where people cheat for different reasons (not excuses, obviously) — being unhappy in a relationship, insecure, drunk/stupid, drugs, etc etc. And especially when people are younger, I do think some are capable of growing up, having a period of self-reflection and growth, and gaining the morals and self-worth not to do it again.

I remember my mum always saying “a leopard never changes its spots” and “once a cheater, always a cheater” when I was growing up. And I do think that’s true sometimes. But is it naive to think people can actually change? That said, personally I don’t think I could be with someone if they told me they’d cheated in the past. It would just always be there in the back of my mind and wouldn’t feel worth the risk of not knowing and the uncertainty. I just wouldn't be able to trust them, personally.

On the flip side, I used to work with a woman who had an affair with a married man (she was also married at the time). They’re now married to each other and have been for years, seemingly happily. She said her ex was abusive and unsupportive, and his marriage had basically died. (Shes a massive over-sharer and told everyone everything, hence why I know all this!) It does make me wonder how that works though. wouldn’t you always have that doubt in the back of your mind? Especially given how their relationship started.

Although I suppose you never really know what goes on anyway, whether someone has cheated or not. If they haven't told you, id just be worried that i had simply not found out yet. Also, everyone who cheats has to do it for the first time at some point, so even someone with no “history” could still do it.

So… what do you think? Can an unfaithful leopard actually change its spots? or is it always the case that once a cheater, always a cheater?

And would you get into a relationship with someone who admitted they’d cheated in the past?

Also interested to hear from anyone who has pursued a relationship with someone that had cheated previously; did it work out or not?

OP posts:
dollytea · 29/03/2026 14:03

Most of the time yes, but not 100% of the time.

MildlyAnnoyed · 29/03/2026 14:06

Yes absolutely. My ex cheated on me, I had him back, he did it again. This went on over several years & now he is definitely an ex because you can’t only put up with it for so long. In hindsight, once should have been the end!

Ilovelurchers · 29/03/2026 17:53

SoSadSoSadSoSad · 29/03/2026 13:56

Did you cheat?

No. My husband did, which is why we are no longer together. I wasn't thrilled about it at the time, but I don't think it makes him evil - we are still friends.

My dad cheated on his abusive first wife, which is how he and my mom got together. No part of me condemns him for it.

If I cheated on someone abusive I would have absolutely no shame about this, and would freely admit it.

Dartania · 29/03/2026 18:24

SoSadSoSadSoSad · 29/03/2026 13:57

Just wait.

How long? One of the couples has been married 25 years! They’re in their early 50s and one of the happiest couples we know. He’s been lucky enough to meet the woman he was meant to be with. His ex-wife is also one of my best friends, and she’d say the same. I’d bet my house on them lasting.

Not everyone that cheats goes on to do it again. It’s just silly to believe this.

carnivalcat · 29/03/2026 18:38

I cheated on my first boyfriend. We were together on and off for 3 years from when I was 14-17 and we both cheated on each other throughout.

I’ve had a few long term relationships since (including my marriage) and have never cheated since and can confidently say I never would. I would happily spend the rest of my life never having sexual contact with anyone but my DH.

So essentially, yes I think people can change, but I would be skeptical about cheating that was relatively recent in their history.

giddyboo · 29/03/2026 18:41

Yes. Once a cheater always a cheater.

Greentea4 · 29/03/2026 18:48

I have belief in people's capacity to learn from their mistakes.

User38512054 · 29/03/2026 18:48

dollytea · 29/03/2026 14:03

Most of the time yes, but not 100% of the time.

It isn’t even most of the time according to the Denver study. It’s a bit less than 50/50.

RedWineCupcakes · 29/03/2026 18:49

SoSadSoSadSoSad · 29/03/2026 13:57

Just wait.

How long? I know one couple who started as an affair who have been married over 40 years since. No sign of affairs.

It is easier to think in black and white than to recognise that life and relationships don't all fit in neat boxes. And that not a cheating is a result of a fundamental character flaw, however much ChumpLady or similar want you to believe.

Needaglowup · 29/03/2026 18:52

The best indicator of future behaviour is past behaviour .. I’m also a firm believer and if they do it once they do it again

pornstarmartinilover · 29/03/2026 18:52

I cheated when I was 18, I’m now 41. I had been with my boyfriend for a year and a half, it was stupid, I was stupid. I did tell my ex eventually. I have never and would never do it again. I hate the hurt it caused and it’s my biggest regret in life. I still beat myself up about it now.
I therefore don’t think that one’s a cheat always a cheat but if it happened more than once, if the person didn’t show remorse the i would think they are capable of it again x

Tontostitis · 29/03/2026 18:53

No, both my current husband, 20 years and first husband ten years were serial cheaters in previous unhappy marriages. Happy people don't cheat. Unhappy ones do. Obviously they should leave before cheating but for men that often means losing their children and in my current husband's case he feels he genuinely tried everything and chose cheating in a sexless marriage rather than leaving. Is it ideal behaviour? No it isn't. Would he do it to me no not in a million years but we communicate really well and if one of us is unhappy we deal with it as a couple.

Tontostitis · 29/03/2026 18:55

giddyboo · 29/03/2026 18:41

Yes. Once a cheater always a cheater.

Utter rubbish. I've done loads of things I'd never do again as I've grown and matured and learnt from my mistakes.

Dartania · 29/03/2026 18:58

Happy people don't cheat. Unhappy ones do

Exactly this.

Notmycircusnotmyotter · 29/03/2026 18:59

No. I cheated in early 20s. Never since and never again.

scarpa · 29/03/2026 19:00

I don't think it's always the case. I don't think it's an immutable personality type, cheater or not cheater. I think some people are more likely to - people who crave novelty or affirmation or attention - and I think a lot of people end up cheating 'circumstantially'. I think the former group probably are more likely to do so again, the latter less so.

scarpa · 29/03/2026 19:02

Also, there's such a huge range of things that fall under cheating. There's a world between a drunk snog on a night out that's immediately confessed and having a years-long affair or a second family. The drunk snoggers/confessors are much less likely to be repeat offenders than the type who keep up an extended lie, IMO.

Sunshinemoonlightboogie · 29/03/2026 19:14

‘Happy people don't cheat. Unhappy ones do’

Absolute bs!

There was a study linked to the Ashley madison site users who largely claimed to be satisfied or greater than satisfied with their primary partner and still chose to cheat. The study changed the thinking around infidelity and we have moved away from the ‘poor sausage/unhappy puppy’ narrative. The study under this title makes interesting reading and might dispel this myth ‘No Remorse: Sexual Infidelity Is Not Clearly Linked with Relationship Satisfaction or Well-Being in Ashley Madison Users’

I’m not saying that unhappy relationships isn’t ONE excuse cheaters use but it’s one of many reasons a cheat might cheat.

This narrative needs to be called out as it directly blames the victim for not making the cheater happy, victim blaming never sits well with me!

BestZebbie · 29/03/2026 19:45

I suspect there is a difference in outcomes between the cheating done by students in fairly short, financially uncommitted relationships deciding to move onto their next partner abruptly (without necessarily informing the first one first) and the sort of cheating done by people who are a little older and have enmeshed their adult lives, where it really becomes 'adultery' (quotes as not necessarily actually married) rather than a 'just' a messy but natural break-up.

The first type have a good chance of growing out of it, the second might or might not continue to cheat in a life-destroying way but they will almost certainly remain primarily selfish underneath a veneer - plausibly too selfish to be a trustworthy partner. Is it better if they don't cheat on you but do walk out if you have a child with SEN together, for example?

hereforthelolz · 29/03/2026 20:08

Needaglowup · 29/03/2026 18:52

The best indicator of future behaviour is past behaviour .. I’m also a firm believer and if they do it once they do it again

Sucker’s maxim.

CaramelGhost · 29/03/2026 20:15

I don't believe, once a cheater always a cheater.

But I wouldn't want to be with someone who cheated. It's grubby behaviour and I wouldn't want anything to do with that.

StephensLass1977 · 31/03/2026 20:49

I do believe if it's inherently in you to do it once, then yes, you are capable of doing it again. I don't know if there's anyone who's so special to a former cheat, that this would take away any temptation forever more.

Cheating is opportunist. So yes, it's a personality flaw.

A university friend of mine constantly cheated on his girlfriends all throughout uni. He was terrible. But oh he's young, people would say. Then he married a stunningly, drop-dead beautiful, very kind woman, and they had 3 children. Oh he's finally settled, they all said. Nope. He cheated on her again and again.

If you're unhappy in a relationship, then, leave before you do anything with a new person.

I was once party to someone being cheated on. The guy told me he was single, and as she was away a lot of the time, I had no idea, and we never went to his house. I'll never forgive myself for that one.

Missj25 · 01/04/2026 00:07

worldshottestmom · 25/03/2026 20:07

I just want to preface this before anyone jumps on me:

  1. I’ve never cheated and never would.
  2. I think it’s awful and I’m not trying to defend it at all.

Just interested in a general discussion really.

So, long story short one of my friends has been seeing a man for a couple of months and it’s starting to get a bit more serious. She thinks he’s great and can see it going somewhere, but her one hesitation is that he told her he cheated on his ex when he was 22. He’s now 31 (she’s 29).

it got us talking about the whole “once a cheater, always a cheater” thing. I’m a bit on the fence with it. I do think for some people it’s just who they are; no real morals, low self-esteem, impulsive, etc, and they’ll always cheat regardless.

But I also think there are cases where people cheat for different reasons (not excuses, obviously) — being unhappy in a relationship, insecure, drunk/stupid, drugs, etc etc. And especially when people are younger, I do think some are capable of growing up, having a period of self-reflection and growth, and gaining the morals and self-worth not to do it again.

I remember my mum always saying “a leopard never changes its spots” and “once a cheater, always a cheater” when I was growing up. And I do think that’s true sometimes. But is it naive to think people can actually change? That said, personally I don’t think I could be with someone if they told me they’d cheated in the past. It would just always be there in the back of my mind and wouldn’t feel worth the risk of not knowing and the uncertainty. I just wouldn't be able to trust them, personally.

On the flip side, I used to work with a woman who had an affair with a married man (she was also married at the time). They’re now married to each other and have been for years, seemingly happily. She said her ex was abusive and unsupportive, and his marriage had basically died. (Shes a massive over-sharer and told everyone everything, hence why I know all this!) It does make me wonder how that works though. wouldn’t you always have that doubt in the back of your mind? Especially given how their relationship started.

Although I suppose you never really know what goes on anyway, whether someone has cheated or not. If they haven't told you, id just be worried that i had simply not found out yet. Also, everyone who cheats has to do it for the first time at some point, so even someone with no “history” could still do it.

So… what do you think? Can an unfaithful leopard actually change its spots? or is it always the case that once a cheater, always a cheater?

And would you get into a relationship with someone who admitted they’d cheated in the past?

Also interested to hear from anyone who has pursued a relationship with someone that had cheated previously; did it work out or not?

It depends 🤷🏻‍♀️.
Obviously there are people & it’s just in them no matter how happy they are with their spouse’s/ partner’s.
The thrill of it, excitement of new sex .
Just can’t be faithful to one person.
Others are in unhappy relationships, & I think once these people meet the person they are most suited to & find happiness with , well then they’re not going to cheat .

Thewookiemustgo · 02/04/2026 10:13

People can change, that much is true. Some people never do and that much is also true.
The black/ white/ grey areas bit I have trouble with. I never feel that two wrongs make a right.
No, if you’re married with children and mortgages etc saying ‘just leave’ is not an easy option, but then doing the right thing isn’t often the easy option. Hence choosing to cheat: I am married and made promises to my spouse but this all feels marvellous, my spouse won’t like it and my life and finances might upend so instead of being honest about my feelings, it’s easier to lie and cheat so that I can have what I want.
Maybe if you’re married with children and mortgages etc you promised never to cheat in the first place and probably shouldn’t choose to do it. That really is black and white.
The grey area comes with the justifications of ‘when is it justifiable to cheat?’ This is where the grey area lies.
Cheating is also abuse. Lying, gaslighting, presenting a false reality, living a double life , taking away your partner’s agency and risking their sexual and mental health is abusive.
To do this you have to be ok with manipulating your partner to unknowingly participate in it all. Their ignorance of the situation they are in means life goes on as usual and the cheat uses that to their advantage.
Their unwitting partner is even sometimes facilitating it (“I’ve got a late meeting on Tuesday so can you pick up the kids for me?” etc) and becomes nothing more than a useful pawn in the game to be used and kept in place until the affair either fizzles out or the cheat uses ready to leave so discards them as if they were worthless to them.
It is not noble to ‘do the right thing’ and go back to your family, unless you are full of remorse, hate what you did and love your spouse. It is entitlement of the highest order to have an affair with your spouse kept in the dark, with no knowledge about their changed relationship circumstances, no informed choice or agency about their lives and futures, and feel noble that you returned to your marriage only because it’s ’the right thing to do’ or because ‘just leave’ is too difficult. The betrayed deserve choice too and should have an equal footing on which to base their decision as to whether or not they want you to return to the marriage given that you are not currently the person you pretended to be.
Just because doing the right thing is difficult, doesn’t change the fact that it’s the right thing to do. That’s why it’s called cheating, monogamous relationships have agreed mutual boundaries and are not a game. See other people if you must, but be honest about it so that others get to choose what happens in the relationship too. They are your equal, a person in their own right, not just useful and convenient.
Cheats need to realise that using people to enable their behaviour, removing their agency and choice and dipping in and out of their marriage vows as it suits them is controlling and manipulative, just because you’re married with children and mortgages doesn’t change or justify that.
Having said all that:
Nobody is perfect. People fuck up, people are flawed, people can realise this and change but have to choose to. I firmly believe all of those things and am nowhere near perfect and am nobody to judge.
However, instead of saying ‘things are never black and white’ ‘it’s never as simple as it people think’ (everybody knows this, life is bloody difficult and messy and tough) to minimise your choices and their impact, recognise that honesty is the life blood of relationships and just own what you did.
Then get honest with yourself as well as others and make amends.
Cheating doesn’t make you a bad person at all, and it doesn’t mean you’ll do it again, absolutely not. But only if you’ve owned it and learned from it.
However, justifying, minimising your poor behaviour and shrugging it off with convenient sayings like ‘life is difficult’ or ‘it’s not black and white’ says you’re good at finding excuses for yourself. It says you’re good at minimising things you know you shouldn’t have done and justifying your own wrongdoing to ease your conscience.
That’s where the lack of remorse lies, it says you’re still not really owning your flaws and recognising that the choice to cheat or not to cheat was your responsibility.
Those people are the ones who are likely to cheat again, because they will always find their excuses and justifications, which won’t ever involve looking inwards at their own flaws, they look outwards usually, to those of other people.
Life is tough, people are flawed, doing the right thing isn’t always easy.
Deep down though, if we get really, really brave and honest with ourselves, we know what’s right and what isn’t.
Even your average two year old knows they shouldn’t put their hand in that cookie jar.

PizzaPowder · 02/04/2026 12:37

I've cheated in the past when i was young and stupid. Would never do it now. I think growing up a lot makes a big difference.