My DS cheated on his girlfriend in my home

[ErsBears]

Hi, so DH and I were away staying with friends over new year, DS’s girlfriend had gone back to her home country to see her family and DS couldn’t as he had to work so I asked if he would be okay staying at ours to watch the dog, he said sure.
DH and I came home early as one of our friends has fallen ill and wanted some space, we went for dinner first then got a train and cab home at about 11:30pm. I didn’t pre warn DS as I didn’t really see the need to. When we got home he was in his room so I didn’t bother him but then DH realised we had no milk, nothing for breakfast and DH had a headache so needed some paracetamol. We have a 24 hour shop within driving distance and both DH and I had been drinking so I went to ask DS if he would mind popping out. I could see his light was on and hear the tv so knew he was awake. When I knocked on the door the first thing I heard was a girls voice saying “is that your mum”. He came the door in his boxers and asked why we were back early, I explained he told me he’d been drinking so couldn’t. Fine. I asked if his girlfriend was back early (I knew it wasn’t her as his girlfriend has a very identifying accent and it was clearly an English accent I heard).

Anyway he admitted he had someone else over, I told him that she had to leave, he booked her a cab and she left. I made it clear to him that either he tells his girlfriend tomorrow or as soon as she is back or I will tell her, I do not condone cheating. He tried to tell me he didn’t sleep with her but when I pointed out he was only in boxers he admitted he was lying. He said he would tell her but they have a holiday booked for next week (she gets back on Sunday, they fly out on Monday).

For context he’s 28, his girlfriend is 25 and they’ve been together for 2 years, they don’t live together but she owns a flat and he was meant to be moving in this year.

AIBU to be bloody raging and so disappointed that this is the man I raised? I am disgusted that he cheated and I think he needs to tell her before the holiday. We are meant to be picking them up on Monday morning to take them to the airport as it’s an early flight. I don’t think I can sit with her in the car and send her off on holiday with him knowing what he has done!

Sadly, I agree. There are so many women who turn a blind eye to, or even justify, sexual and physical violence committed by the men in their lives, and I feel like some of them are on this thread. It's so disheartening.

But it's a real eye-opener to see just how many there are!

And a wee post from you not realising this was cleared up a few pages back.

Which would be yet further evidence of his disrespect and inability to take responsibility for his own actions.

They're probably the ones desperate to have any man in their life regardless of how horrid he is, rather than be single.

This thread confuses me. This is MN right? There cheaters no matter what are the worst people in the world and once a cheater, always a cheater even if you were 12yo amd held another girls hand.

Now it is totally cool to go on dating apps and sleep with other girls cause it isn't a big deal since they aren't married. If you know about cheating, keep it to to yourself and just happily let person plan their life with someone who is active on tinder.

I see this as two things: the first is your own morals - you have a right to be outraged, you have a right to be disgusted, you have a right not to give them a lift, to have her over etc.

However, it is also none of your business, and you shouldn’t be meddling in the affairs (quite literally) of others. The world isn’t as black and white as you are making it out to be.

My advice would be to talk to him, encourage him to come clean and why, and then leave him to it.

This is why in 2026 we still have sooo many men behaving atrociously towards women. A lot of mothers don’t teach their sons properly and will allow them to grow up to be twats.
Good for OP looking out for the girlfriend.
Obviously many of you on here wouldn’t care. Wonder how you would feel if you found out your husband/partner was cheating and his mother knew..??

Good for you OP - you have integrity. Maybe once your son has told his GF and seen the damage he has caused he will develop some too. Cheating is one of the worst things you can do to someone, it causes so much pain, he should be ashamed. If he really loved her he wouldn't have done it.

Oh yeah. When people talk about interfering MIL's, this is exactly what they mean.

That bitch of a MIL made my partner tell me that he downloads Tinder when I'm out of town and hooks up with randos from the app. The audacity to inform me before I let him move into the house I own and paid for and potentially give him half of the asset. MIL just keeps interfering and won't let me be happily oblivious while he downloads dating apps whenever I see my parents

I applaud you OP, both for refusing to accept terrible behaviour from your son and making that crystal clear to him, and for looking out for another woman. Every time we hear about a cheating, feckless man it always comes back to how we need to parent boys better so they treat women better and here you are doing that and taking your responsibility seriously even when he's an adult. If only more people realised that enabling the kind of behaviour you outline isn't actually supportive of your child.

He doesn’t live with her. This thread should go into classics as an example of a thread where multiple people can’t read.

@ErsBears it sounds as if he is only concerned that his behaviour will end his relationship but doesn't actually think he's done anything wrong. Which is the sad and annoying part. I would probably tell her as it sounds to me as if he won't.

I also bet that the girl who responded on tinder didn't know he was in a relationship so also couldnt give proper informed consent either.

I agree that you should not drive them to the airport unless your son has told his girlfriend. Why would he not respect her enough to give her the choice of continuing on with a cheater?..
He is using this woman. He is not honest.

This thread is quite enlightening! We see thread after thread of PPs, DPs and DHs, treating them atrociously. And the immediate cries of call Woman’s Aid, call the police etc, etc!

Well one thing that is clear here is don’t call the MIL!

I used to think that MILs got a poor deal on MN. Now I am not so sure. Be weary women, you could end up with one of these enablers as yours.

And I am a MIL, whose SIL sees me as more of mother figure than his DM. He says that he respects me because I tell it as it is, whereas his DM supports him in anything he does good or not so good, and just tells him it will all be alright.

My SIL would be more frightened of my reaction to any such behaviour, than my DD. And he absolutely loves me for it!

How’s it his home?

I know, shocking isn't it? By this logic all affairs are OK as long as we don't find out.

You see it with posts that clearly make child abuse level worthy of reporting in school "mind your own business" yet if more of us stepped up and said something woman and girls like Sara Sharif might be still alive. Not only does this thread show it's OK for the men we are close to, to behave like shits without being pointed out, but it's also for women to be treated like shit.

So what hope is there for women and girls? Because here is a mum trying to say to her son "do better" and being pulled down for it.

Where do better men come from? Who can held there actions up to them? Which makes me think I'm not better off telling my sons to respect woman but need to invest that energy into teaching my daughter to trust no man fully ever. Even her own sons? Madness. What exactly do we want?

No it isn’t.

Cannot believe the amount of stick for OP and condoning comments on this post! Well done OP for calling your son into better behaviour.

Because he did it in her home. This thread is so frustrating because people seemingly can’t read properly!

I’ve reported that post 👍

He’s done it under you roof, you caught him and now he’s made it your business. He’s been an idiot. Not only is he taking away her right to consent to sleeping with him not knowing that he’s slept with/sleeping with other people, I bet she wouldn’t want him moving into her home if she knew. I wouldn’t tell her but I wouldn’t be driving them to the airport. I’d be having a very big conversation with him about everything that’s been pointed out here. I’m sorry your son has put you in this position.

It’s shady behavior OP and you are right to be concerned.
Theres a whole trend on Instagram of women catching men who have profiles on tinder.
It was premeditated and planned for the opportunity…GF out of town DM/DD out of town and house available.
He’s a cheater. He may have cheated before or this is his first but not last effort at it when he thinks he can get away with it

And he used your dog as a beard.

and then I would say more but @Nopersbro said it best. Worth rereading this earlier post

But you quoted an entire post and made a sarcastic jibe implying that the poster hadn’t read the OP properly. Yet that poster you quoted had already admitted they were mistaken. Pages ago. Can you not read?

See? Easily done.

Did you mean “none”? It’s her business as it was her son in HER home.