Friend is having an affair both are married.

[Themind]

My friend has been married to her husband for 10 years two girls age 8 and 5. As far as I am aware no particular issues with their marriage we have been friends for about 6 years and re quite close. Husband seems like a nice guy but I don't know him as well. I was aware about two years ago she'd had a fling but it had allegedly ended before she'd told me. My husband and I went to the theatre yesterday and ther she was with the man she'd had the fling with earlier. She realised I'd seen her and looked shocked but sat down so I didn't approach. Queue a phone call this morning and several others throughout the day begging me noto to say anything to her husband. She confessed that she had never ended it with him first time round and had carried on cheating. He has lots of money wife doesn't understand him all the usual tripe and he won't leave because his wife will be entitled to half his cash.
She loves him apparently and would leave her husband in a heart beat. Please tell me what to do? I have a incline to walk away and never talk to her again, my husband suggested give her an ultimatum and tell her that if she doesn't tell him I will. I'm scared to death that I wouldn't want to be responsible for ruining their girls lives but ultimately she has cheated her husband and children hasn't she? I'd rather know I I was her husband.
Any ideas welcome, I hate this.

With equal respect, I'm not the one claiming to be the authority. I'm actually saying the opposite. Neither I, nor anyone else is an authority on what's right for other people. Its the people who remain convinced they are right to disclose affairs who are guilty of assuming authority. They are unshakeable in the belief that they are doing the right thing in involving themselves and that their opinion is the only one that's valid.
If my viewpoint is set in stone, well that doesn't translate to potentially harmful action, does it? I'm just harmlessly commenting on here. If people are unwilling to consider other views (and i really can't see any examples that show people on the other side of the argument doing so, can you?) before wading onto other people's lives then they on the other hand, are something of a liability.
And I'm not offended in the least, nor do I think people are out to get me. Its theoretical not personal as far as I'm concerned.

Finding out you're being cheated on when you believed you were in a monogamous relationship can be disconcerting, putting it mildly. I think I would rather be told kindly and gently by someone I knew rather than find out later that some people knew but thought it none of their business. I would feel abandoned by those people who knew but who had kept quiet, I think.

End friendship and keep out of her drama

@EnterFunnyNameHere I agree ten fold. Staying friends, for a while, with someone who was being unfaithful is on the list of my life regrets. Her exDH is very gracious in still speaking to me but I feel ashamed of myself even years later.
I wanted to be the supportive, non judgmental friend but actually I was being spineless because I didn’t want to lose a friend. A friend that turned out to be the complete opposite of who I thought she was.
The sister of the man’s wife collared me once & asked ‘who is friends with people like that’. It’s still rings around in my head because it’s absolutely true.

Having an affair for years takes a special type of character. This is not a drunken shag or a fleeting liaison. It’s a long winded lie that this woman tells EVERY day in many different ways. It’s calculated & sinister.
In my opinion you have to be a bit unhinged to live like that. Who in their right mind could be bothered?

Are you seriously trying to compare a partner going out for a drink with friends in their spare time to one having an affair in their spare time?

On that basis I suppose you'd think it was fine for someone in a relationship to be seeing prostitutes in their spare time? As long as they're contactable in an emergency obviously. 🙄

Having an affair for years takes a special type of character. This is not a drunken shag or a fleeting liaison. It’s a long winded lie that this woman tells EVERY day in many different ways. It’s calculated & sinister.

I agree, it takes a particular kind of bottle (not in a good way) and a belief that you are absolutely entitled to whatever you happen to want and that you deserve more from life than you are getting. OP will be saying to herself whenever she is with her rich lover “ I deserve this”

There was a similar post recently about a neighbour seen kissing another women.. and whether to tell the wife. The answers were pretty much the same. Mine certainly was.

Have you actually talked to her about how this makes you feel, OP? You've clearly had several conversations with her since seeing them together. When she tells you she'd leave her husband if the OM would leave his wife, what do you say? Have you told her she's a mug/a reprehensible witch/storing up a lifetime's unhappiness for herself and others/putting you in an impossible position? And how does she respond to what you say?

I can't understand why you're discussing this here instead of with your friend herself. When you come back to the thread tutting about how "elated" she is, it sounds as though you're enjoying the drama tbh, which may be part of the reason people are advising you to think twice before saying things to her husband that can't be unsaid.

If it's difficult to have that conversation, maybe you could just send her a link to the thread. That way you probably don't have to worry about whether or not the friendship has a future.