Meet the Other Phone. Only the apps you allow.

Meet the Other Phone.
Only the apps you allow.

Buy now

Please or to access all these features

Relationships

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:
Goldfsh · 26/03/2026 09:35

I cheated when I was young - and I quite enjoyed it. I was not in very healthy relationships at all though, or a healthy psychological place.

Would I cheat now? Not in a million years. I want different things from life: stability, loyalty, companionship. What's important changes as we get older. And you mature emotionally, psychologically and spiritually as a person and understand the importance of a more value-based way of living.

Also who has the energy?!

Scottishskifun · 26/03/2026 09:54

User38512054 · 26/03/2026 08:42

So, what about somebody that first cheats in mid life, do they then automatically become serial cheaters from then on?

My experience says not.

Someone who cheats mid life is definitely more aware of their actions and ramifications then someone at 18 years old.
In that scenario I would think they would be more likely to cheat again yes as they have shown they will make that decision knowing the full impacts.

dailyconniptions · 26/03/2026 09:59

No. Of course people can change.

User38512054 · 26/03/2026 10:03

Scottishskifun · 26/03/2026 09:54

Someone who cheats mid life is definitely more aware of their actions and ramifications then someone at 18 years old.
In that scenario I would think they would be more likely to cheat again yes as they have shown they will make that decision knowing the full impacts.

Regardless of age, if it is their first time, they are unlikely to appreciate the full impact until they do it.

Villanellesproudmum · 26/03/2026 10:09

Something from a decade ago, ridiculous, doesn’t mean he will now.

GarlicFound · 26/03/2026 10:29

A few people have touched on another factor that must be at least as important as love and sex - general dishonesty. For a large number of people, everything is theirs if they can get it by fair means or foul. They feel like winners when they get away with breaking rules or laws.

My first husband lied about his professional qualification. The second left a trail of small-scale frauds in his wake. Both were prone to stealing daft things. Both cheated on me multiple times. I'm not saying I've never wrangled an expenses claim or lied about being ill when I'm lazy - and that's probably why I overlooked this character flaw in my partners. But with them, it was methodical.

It's taken me a very long time to understand that someone who 'sticks it to the man' as a life principle will stick it to you, too!

Badballerina · 26/03/2026 10:30

I don't think once a cheater always a cheater. I cheated on Ex Husband in a long term marriage. It was an awful marriage and in retrospect I should have just left early on - there were cultural, social , geographic and religious pressures which make me stay. I was full of self loathing for cheating. It all ended horribly. I'd never do it again. I've been with my second DH for 20 years - he's a wonderful man, he is so good and I'm so happy- i'd never jeopardize that

beadystar · 26/03/2026 10:32

To add, some people also don’t seem to be ok with being alone, even briefly. It’s curious. So they replace their person rather than ending or working through a failing relationship, which would include seeing their own part.
My first love who broke my heart (through cheating) at 21 has not been single for even one day in the 20 years since. There have been 4 more partners, and each relationship ended in cheating and going off with the OW… and the pattern will continue because ex has compartmentalised and ignored the trauma their actions left rather than taking accountability and grieving.

MrThorpeHazell · 26/03/2026 10:38

No, I don't. I know a couple of serial cheaters - one man and one woman - but I also know 5 or 6 cheaters who ended a relationship and who, so far as I can see, have remained faithful to their new partner.

"Once a cheater always a cheater" is just a sweeping generalisation and, like all such, "it ain't necessarily so".

piscofrisco · 26/03/2026 11:09

Yes. I think there is something in most cheaters that means their ego needs to be fed in this way. They get bored after a time and feel small and need to chest to have their ego fed and to feel alive again. They might go years being faithful but the itch is always there and they always believe theirs is someone better than their current partner that they deserve to have.

SleepingStandingUp · 26/03/2026 11:15

I cheated on my ex when I was a similar age. I was, in retrospect, deeply unhappy and still in love with the guy I cheated with. There had been some low level stuff but the day after I had sex with him, I broke up with my boyfriend.

I've had several relationships since the, married 13 years, never even been tempted and now old enough to understand that wanting to is a red flag to myself.

Not everyone can be perfect. Some people have to fuck up once to learn

SleepingStandingUp · 26/03/2026 11:24

OrlandointheWilderness · 26/03/2026 08:59

yes.
if someone could justify it to themselves once then they could again.

But I used to get so drunk I could barely stand let alone keep myself safe. That didn't mean I did it every time I drank and it doesn't mean that I didn't learn my lesson.

I once tested the hob temp with the flat of my hand. I was 15 ish? 30 years later I've never done it again.

Yes some people dgaf and enjoy the thrill / power but a guy saying "I did this 9 years ago" is hardly a hardened cheater.

By the logic of some on this thread, anyone who's ever done anything wrong is destined to repeat that forever. No one is allowed personal growth or mistakes.

God it mict be hard work being so morally perfect and superior

AlmostAJillSandwich · 26/03/2026 11:41

No i don't think they can change.
I've always firmly believed there is NO excuse for cheating. If you're unhappy in your relationship you end it, not hold on til you find someone you want to be with and figure out if it has potential legs before leaving the person you were with.
I also don't think "I was drunk" holds any weight either. You chose to drink as much as you did, if thats led to you losing inhibition but being capable of consenting still and you have cheated, thats your fault. (Obv rape and SA don't count if they were past the point of knowing what was going on and consenting)

To be able to cheat on someone means being capable of having zero respect for your partner, of crossing their boundaries, and lying to them. It is very likely that they will lie to, cross boundaries and disrespect their subsequent partners in many ways other than just cheating on them. Those are personality traits i just wouldn't accept in a partner. I just left my fiance after 5 1/2 years for doing all of the above.

OrlandointheWilderness · 26/03/2026 12:04

I’m not morally perfect or superior @SleepingStandingUp- but I do have morals that I live by, as does everyone. We all have slightly different values and things we hold higher than others. It just so happens that due to my upbringing, childhood experiences of the damage cheating causes and experiences from past relationships that fidelity is a very secure value. In my head you do not cheat is up there with you do not kill or you do not attack old ladies or steal babies! It’s just absolutely not in my nature and for me to go against that would cause moral injury. That doesn’t make me perfect or superior- just different.

OneShyQuail · 26/03/2026 12:25

BoudiccaRuled · 26/03/2026 08:27

I used to agree with this but know two men who married at haste, cheated a great deal then ran off with their mistresses whom they were then married to, seemingly very happily, for decades until death divided them.
Being weak, a coward, and not being able to pluck up the courage to leave in a civilised manner does not always equate to "once a cheat, always a cheat" in my small experience.
But I still wouldn't go there!

Well they met their match didn't they? The mistress also had no morals 🤷‍♀️

Whose to say they didnt cheat again. Its more likely when they've done it once. They have shown themselves to be untrustworthy. Marrying "at haste" also massive red flag....why marry at haste?!

Even worse imo.....the only woman he made a life with was a mistress.....go figure 🤦‍♀️

User38512054 · 26/03/2026 12:44

OneShyQuail · 26/03/2026 12:25

Well they met their match didn't they? The mistress also had no morals 🤷‍♀️

Whose to say they didnt cheat again. Its more likely when they've done it once. They have shown themselves to be untrustworthy. Marrying "at haste" also massive red flag....why marry at haste?!

Even worse imo.....the only woman he made a life with was a mistress.....go figure 🤦‍♀️

Who’s to say they didnt cheat again. Its more likely when they've done it once.

More likely, but by no means a certainty.

User38512054 · 26/03/2026 15:28

Once a Cheater, Always a Cheater? Serial Infidelity Across Subsequent Relationships

45% of people who reported cheating in a first relationship did so again, compared to 18% of those who had not previously cheated.

  • Someone is three times more likely to cheat if they have cheated in the past.
  • A person is two to four times more likely to be cheated on if they have been cheated on or have suspected cheating in a prior relationship.
  • Men and women are equally likely to cheat or be cheated on.
  • A person's likelihood of cheating is found, not in a single demographic characteristic, but in a complex combination of factors, including cultural values and available partners.

https://link.springer.com/article/10.1007/s10508-017-1018-1

Once a Cheater, Always a Cheater? Serial Infidelity Across Subsequent Relationships - Archives of Sexual Behavior

Although there is a large body of research addressing predictors of relationship infidelity, no study to our knowledge has specifically addressed infidelity in a previous relationship as a risk factor for infidelity in a subsequent relationship. The cu...

https://link.springer.com/article/10.1007/s10508-017-1018-1?error=cookies_not_supported&code=27d29afa-44bc-4307-a176-055cf1ce6949

FloydPink · 26/03/2026 15:43

Everyone makes mistakes - I have done things wrong in my past but the key thing is not to repeat them. People cheat because the relationship is not giving what they want/need, and while its easy to say they should leave it sometimes starts just by getting closer to someone you shouldnt over time and then lines get blurred.

Of course there is some serious stuff that could have happened but if a partner told me they cheated once previously it would not bother me.

worldshottestmom · 26/03/2026 16:18

CarrieMoonbeams · 25/03/2026 20:50

My parents had a horrible marriage, they were absolute poison together. My dad was physically, emotionally and financially abusive to my mum, me and my brother. (My mum was "just" emotionally and verbally abusive to me and my brother.)

My dad had constant and multiple affairs all throughout their marriage, with no attempt to hide it at all. Quite the opposite actually. Looking back now, I'm certain that he deliberately left 'evidence' in his pockets, knowing that she would check and find them - receipts for nice restaurants when we constantly went hungry, receipts for clothing and jewelry from high end shops etc when we had clothes from car boot sales. It was all designed to punish/hurt her, obviously, and she never said a thing to him about it because she was too scared of his reaction.

When they eventually split up, my dad became a serial monogamist! He was incredibly generous to his friends, neighbours, partners and AFAIK he never lifted a hand to anyone for the rest of his life. He obviously just hated us.

My mum did go on to have have 2 other relationships but they both cheated on her, one in his 60s and the other in his 70s.

That sounds so bloody awful and I'm really sorry they put you through that, especially your vile dad. Mine was similar, though much more secretive about the affair, and the abuse didn't stop with us.

Interesting though that yours then became monogamous once he left. I think this was probably more to do with himself and his personality type and own mental issues, as well as just not caring for who he was with (your mother). Obviously not an excuse, but was an interesting read in terms of the change around of his behaviour.

I hope you and your family are okay now, truly.

OP posts:
Beenthroughit · 26/03/2026 18:31

TheFormidableMrsC · 26/03/2026 08:00

My ex husband was a prolific cheat. I didn’t find out much of the extent of it until he left and I probably will never know the whole truth. I don’t need to know now, I have made peace with the betrayal. However, the OW he left for was deeply insecure and tracked him everywhere. He won’t stop, it’s part of his very being I believe. He is definitely a case of once a cheat etc….

I certainly don’t think this applies to everybody though. I have a family member who did it and it was complicated and abuse involved. They never did it again.

Turns out that now ex was a serial Cheater most of the time through our long marriage. All very well hidden.
I don't imagine he's changed with his affair partner, who has known us as a family for 20 years
If someone was young, not in a committed relationship, and had grown up and honestly regretted what they had done, and had learned what a sgitty thing cheating is and has viewed to never do it again, maybe give them a chance. He would need to be wholly open about what he did, where he went etc, but having said that, would I want to be the marriage police for the rest of my life? Wouldn't it be much nicer to have someone who had finished one relationship before moving on to another one. Now-ex was perfectly happy having someone at home he could rely on to be the wife appliance always there because she didn't know about his secret life , and someone else for a bit of excitement on the side.
I wouldn't have someone who I knew had cheated, in my experience they stay spotty

Beenthroughit · 26/03/2026 18:40

The way Iook.at it would you employ an accountant or bookkeeper who had been caught cooking the books or embezzling the firm/clients they were working for? Would you be pleased to leave the money/banking wholly in their hands without checking on everything? If you cannot trust them without checking every last little thing they do, it would be much better to get an honest accountant/ bookkeeper who would do the job honestly, and keep everything above board

MsPepper · 26/03/2026 18:42

A cheater is a liar. So for me, I wouldn’t knowingly go there.

SeekOIt · 26/03/2026 18:53

I think it's a part of their character and it's who they are.

TheIceBear · 26/03/2026 19:02

No I don’t think so . I think it depends on a lot of different factors . It’s not as simple as that . I had the odd drunk kiss here and there in various relationships when I was younger but I’ve never ever had sex with someone else when in a relationship. Now I’m married I woudn’t cheat at all I would sooner just end things than do something like that

Hotterthebetter · 26/03/2026 19:33

My husband and I have been together 36 years - married for 30.
we’d been together 5 years when we split up as we just felt things weren’t going anywhere. We were too young, having met when I was 20 and it was no fun being saddled with a mortgage when rates were 15% and it seems all we did was work to pay the mortgage and bills. There was NOTHING left to do anything fun. 😢
After a year apart, we started seeing each other casually and he wanted us to get back together. I was unsure for a while
but he was persistent 😃 I said we could but I wanted real plans for the future eg marriage and children and he said he wanted the same. I also wanted complete honesty about the past and asked if he’d ever cheated. I told him he could tell me and I would never hold it against him. He said he had cheated once. I was floored by this as I really wasn’t expecting it. However I decided to take a chance and I can honestly say, as much as anyone can, that he has never cheated again. We married, had children and have recently taken early retirement together. We have a fantastic life and I am so glad I took the chance all those years ago.