Should I tell on a cheating spouse?

[NessaVanessa]

Went out Friday night with some friends to a club in London. I have a friend called J - Not childhood friend, but we are friendly enough, we know each other as our DC are going to the same school. J has a spouse - M - who I saw in the same club with a small group, don't know if it's friends or coworkers, doesn't matter. M did not see me. Most of their group left after a drink but I did see long, handsy snogging between M and the only other person that stayed. At one point I thought they left because they disappeared but then walked back from where the toilets are. Ew. I am not saying something happened in there, but I wouldn't be surprised either.
I know J loves M and it would be heartbreaking to learn. They have two kids, I thought they are super in love. So I don't know what to do.
Should I tell J what I've seen M doing? I took a few blurry videos from a distance. You can imagine it's not great quality, but I think M is recognisable if you are familiar.
What would you do?
(edit: Name changed)

Very indeed.

You’ve responded sensitively to what I posted above, but based on this seem not to have understood what I was saying? It’s not wrong to be selective based on real sex-based risk.

Can I just say that not once did @NessaVanessa imply that M is the man and J is the woman, and some/most of you immediately assume it being the case.
I have a feeling there is a reason the "he/she" parts are left out from the post.

Read the thread 🙄 . Second post

I don't know who her close friends are.

It is rather complex, isn't it, the world is hardly black and white. It is difficult, because what has happened to you is a horrible, unfortunate event that nobody should experience. Based on that, it is easy to get to that conclusion to just not speak up when someone knows about infidelity. But I don't believe it is right to land at the conclusion that men don't deserve the same level of truth "just in case". Does that make sense? I don't have a happy medium, or a solution, but that clear-cut separation cannot be the solution to this..

How is it complex to know that men are statistically MUCH more likely to be domestic abusers and violent than women.

Actually I am not keeping my distance as advised to other posters so ignore

Yep, I’m on this side of the fence. Tell. Always tell. What she does with the information is up to her, but you should always tell.

This is true. I wanted to avoid judgment, because I am friends with a man, and a lot of women here don't seem to take kindly to that. M is the woman, and J - my friend - is the man. I didn't want people to assume that I want to blow them apart, not at all, I have my own partner.

Does this mean that M doesn't deserve the truth? because he is not a fellow mum?

I responded to the original "you are not close to her at all" post and kept the "her". Sorry .

So why when I asked about J’s close friends did you say you don’t know any of her close friends?

well now know M is the woman, and you don’t really know J the man - no I wouldn’t tell

If you wanted genuine advice, the genders were relevant as revealed by quite a few of these responses.

No I wouldn’t tell not tell a man I barely knew that his wife had cheated on him

That is reasonable.

You barely know M
what we do know is that he is a man
and going back to you barely knowing him - I wouldn’t tell not risk telling him something
given, you know, the wealth of evidence that men are far far far more likely to be domestic abusers behind closed doors than women

Ok thank you. You made your point.

so you’re going to tell him

ok, well I hope M is ok

Ok, you made it very clear - typing up 3 consecutive responses in a row that now that you know J is man he doesn't deserve to know what his wife is doing. Ok, I heard you the first time. Thank you.

I am so sorry this has happened to you @UnintentionalArcher . I have no doubt something like this can shape how you view this situation. Heck, I think it would shape anyone's. I hope you got the proper support....

I want to know who's the man and who's the woman

J - my friend is the man.
M - the wife is the one who was out snogging someone

Id tell noone else but i would tell her. Id text to arrange a coffee say its important then tell her what i knew.

Id want to know. Id also want it to remain confidential so i didnt feel judged if i decided to keep the family together.

Men are so disappointing...

Many years ago I told my then best friend that her husband was cheating . She had always said she would want to know as her previous partner had cheated ( unknown to her) for years and no one told her .
She never spoke to me again. I would occasionally see her in the street and she crossed the road . She stayed with him until her recent death .

It's the wife doing the cheating, and my friend is the man...
So I am guessing anyone can be disappointing, it seems.

That is horrible. Well, for what it's worth - you did the right think, and the joke is on her.