is this unforgivable in a friendship?

It’s pretty close to justifying it when the OP is confused about whether it’s unforgivable in a friendship and most posters have told her that it is. The man isn’t in the friendship group, his marital status is irrelevant.
Is it shitty and untrustworthy all around? Yea. Is an emotional affair between a friend and your spouse the end of the friendship? Yes, for most clearly it is.
Is an emotional affair the end of a marriage? That’s not the same for every marriage.

Absolutely spot on. I hate this ‘poor ickle me I’m so silly lol’ type posts where the OP plays with fire, gets burnt and tries to play the naive innocent victim.

Shit on your own doorstep and there’s consequences. Of course he’s a sleazy dirtbag but he couldn’t play these games without a willing playmate and the OP was happy to betray her friend for a cheap thrill. I hope it was worth it love - and as for the single mum card - oh fuck off with the excuses. 99% of women know to to flirt with and encourage their friends husbands to flatter their ego. Being a single mum is fuck all reason for having an EA with your friends partner. And now you’re ostracised - boo hoo cry me a river. You should have shut him down the very first message - but hey I’m sure the attention was worth it!

Find new friends and this time leave their husbands alone.

IIt is easier to blame OW than admit husband at fault.

Why would she return to a thread where so many place the blame at her feet and none at the man's? Her OP was never about justifying what she did, it was about why she is ostracised but the man will likely remain part of the group.

Move on. Don't contact her or him.

To answer your question « is this unforgivable in a friendship? »

Its absolutely unforgivable.

Surprise fucking surprise - no replies from the OP.

On the slim chance you’re actually reading these replies - you need to develop some autonomy and take a massive bite of a reality sandwich. You could have blocked him at any time. He hasn’t forced you into anything, whether he “1000000%” drove the messaging or not - and given that you replied (even if just to tell him to stop) and never cut off the lines of communication, you were certainly never discouraging him, even if you didn’t lay it on a plate.

And of course his wife isn’t treating you as both equally to blame. Why would she? It’s not like she’s reading the thread on her and making an assessment. It’s her fucking marriage! Maybe she would be better off without him, but that’s not for you to decide. Ditching a random woman from a WhatsApp group is a damn sight easier than ditching your husband, whether he’s a sleazebag or not. You weren’t a good enough friend to tell her husband to fuck off and block him after the first message, so why on earth would she consider you a good enough friend to say “Fair enough, we all make mistakes, there’s blame on both sides”?

Grow up a little bit and move on.

I'm not going to knock you while you are already down but while I get it that nothing physical happened, you clearly had an emotional affair with him. If you got to the point where you admitted feelings, a lot of chats must have happened before. Be honest with yourself , were you texting brfore you decided to not encourage his latest messages. Is it possible his wife found these?

As for the blame thing. You described her as a good friend. Imagine finding out your good friend and husband told each other there was feelings between them.

And I suppose finally - your friend group, I would expect her friends to support her, not you I'm afraid.

So it always goes. You stepped over a line, he danced over it and continued. You were always going to take the fall.

Your friend is a fool, her husband is a twat. What are you? Don't engage with married men on any level except professional because you will always come off worst.

Contrary to what posters always say that 'he wants his wife'. No. No he doesn't. Men who want their wives don't cheat. You may have triggered many cheated-on wives here but they also have the choice to back out of the thread rather than read it and cause themselves pain.

Put this behind you, take your conscience pangs and feelings of 'not fair' and resolve not to let this happen again.

YABU. It would have been simple to block him, yet you never did.
Yes, he is the main one at fault. But you are not 100% blameless.

You and him have behaved like immature selfish brats to be honest

It’s very simple; don’t mess around with someone else’s husband. There are plenty of other men out there; why become so close to a friend’s husband? You’re in control; things don’t just happen without active participation. He sounds like a complete scumbag, sending messages behind his wife’s back.

I doubt he has got off lightly; I’m sure his wife’s giving him a hard time behind the scenes. If she’s discovered the messages she’ll be reeling with shock, it could even break up their marriage. As it’s broken up your friendship.

Take some responsibility for the situation and keep away from married men.

As a single mum with lots of married friends whose husbands are mainly wonderful, eligible men, YES, it's absolutely unforgivable. Even if a friend's husband was someone I'd be interested in if they were single (a couple are), I just couldn't think about them in that way.

You should have stopped this as soon as it started and then you wouldn't have developed feelings for him. Of course she knows, why else would she block you. Of course everyone is going to distance themselves from you, they will be afraid that their husband will be next.

She can cut you out of her life, but she may wish to forgive him and keep the family together. That is her concern, but she is doing what a lot of women would do. You have to accept that your time with this friendship group is now over.

Get some counselling and work on your self esteem and get help to make better decisions.

I am a single parent and that has nothing to do with making choices like the one you made. Friends partners/husbands are 100% off limits, you don't even think about them in that way, whether you are single or married!.

Yes, it's unforgiveable in a friendship. You did the right thing not acting on it but she clearly does know and has - inevitably - chosen her husband over your friendship. He doubtless told her it was all you and not him. I don't think there's much you can do but block him and try and put the whole thing behind you.

What would you have done if the DH had said I will leave my wife for you? I do not think you are any friend at all and if I were the wife- or any of the other friends in this circle I would be blocking you.

Now that it’s finished it’s best to put the mess behind you and move forward.

She's seen some of the messages. Either through luck as to what she's seen, or a willingness to be in denial on her part, he has managed to persuade her you are a crazy woman who chased him. Not sure why you're surprised. She has made a life and family with him, cares for him far more than she would you, and has far more to lose practically by blaming him than blaming you. Its almost always the way that the OW shoulders the blame.

Married man gets bored. Starts sending signals to everyone to see who will pick up on it. Woman who does and thinks its like some Mills and Boon novel where they would be together if only the universe wasn't keeping them apart. Man gets caught somehow and blames the woman. Woman gets ostracised.

This is spot on. I honestly believe OP isn’t the only one this man has tried it on with. He was bored and restless and decided to get some attention wherever he could find it. She may well be the only woman who reciprocated as much though.

You fucked up. The only difference is that its easier for her to get rid of you, she has ties to him.

Exactly. This whole thing was sadly predictable.

I have to say this is why I’m glad most of my friendship circle consist of people (married and single) that I’ve known for most of my adult life and they are thoroughly decent people with strong morals.

Reading Mumsnet I feel a lot of these “mum groups” are friendship of convenience that are cobbled together because their kids go to the same school or whatever and the women don’t genuinely care about each other. Thats fine,as there are different kinds of friendships but the issue is when you think you’re closer to someone than you really are.

I doubt any woman will want to be friends with you if you have a history of messaging someone else’s husband on the sly. Shows your (and his!) true colours/lack of morals and values. Also massive lack of intelligence to be honest…where do you think it was heading?! Why on earth didn’t you just block him. The whole ‘soulmates’ rubbish is a story as old as time. He just wanted the excitement of a cheap shag with someone else…you could have been anyone.

You sound like deep down you are loving the attention and hope he will leave her for you. Jesus.

I appreciate your honesty.
I have been on both sides of this.
While you probably have some guilt, good on you for making sure it didn’t evolve into more.

I think she probably does know and will defensively try to distance herself (and mutual friends) from you in a way that is quite understandable given the hurt.

Where I think your assumption is wrong is ‘if she knew she wouldn’t be with him’. Wrong. Most women will stay with a partner even after a full blown affair. The couple talk it through, women get apologies and assurances that it won’t happen again, and they decide to give him another chance. I did.

Because although it is hard, it is often easier than the prospect of breaking up your family. It is also much easier to mentally assume/convince yourself that it was all the ‘other woman’s fault’ than to face the reality that someone you thought you knew, loved and trusted could be the one to lead on something like this (and he may well have misrepresented the situation to her to minimise his role).

It will take time but you will move on, and be happier for it.

Where did my post say anything about maintaining the friendship? OP knows the friendship with this woman is over!

This is about the man not passing the blame to the woman.

You dont allow close friendship to develop with friends husbands. You just dont allow those situations to develop, even if theyre attractive. Even if you get on well.
Wtf is wrong with you. Have you never had to fend off a mans attention before?
What a cliché.

Yeah, ageee - I don’t see how OP can infer that either she doesn’t know or that he’s come up smelling or roses; in all likelihood neither are true and she’s crushed by the betrayal of both.

Of course it is on him.

but the OP seems to think her friend will carry on with the friendship like she’s played no part. Her question literally is ‘is this unforgivable in a friendship’ and the answer seems to be for this friend ‘yes’.