AIBU to not forgive SIL affair?

[Ambs81]

This is a complicated one- but I'll try to tell the short version! Any advice, especially from those who've experienced similar would be great.
Last year I found out a work colleague had split from their husband of 10 years after finding out he'd been having a 6 month affair with a younger women, who was known to my work colleague.
Like anyone, my work friend had completely broken down, she'd confronted the girl he was having the affair with -who she knew well and after a few days, rang the fiancee of the girl involved to make sure he also knew what had been going on.
She found out when typically, her idiot now-ex-husband had left his phone with hundreds of photos, video, messages from the other women in an archived chat. Most of it was quite sexual, but they had also told each other they loved each other, and discussed plans to leave their partners (talking solicitors for divorce, living arrrangements).
The plot thickened when a week later, it was mentioned in passing the name of the finance of the girl involved in the affair - it was my brother in laws name (my husband's brother). Its not a very common first name, or surname (now my surname), i was surprised my work friends hadn't already made the connection.
We quickly confirmed it was my BIL financee (they are due to get married this summer), I was shown some of the images / video involved and it was clear she was the guilty party, I also noticed she'd come off social media at this point.
I obviously told my husband, and explained his brother already knew what had gone on - but encouraged him to talk to his brother and support him through the fallout.
His brother was extremely upset we knew, and as his fiancee had managed to convince him the affair was just text messages, not sex, our input confirmed that it was sexual (i watched footage of them having sex!), which obviously caused my BIL more upset.
Long story short, 6 months later and my BIL has decided to stay with the his financee, after 2-3 days living apart, they decided they were both to blame and wanted to stay together.
My BIL suffers from depression, and it seems as though the family feel this caused her to have an affair, as he was distant and not meeting her needs. As someone who has suffered with depression, I feel really shocked that this is being used to justify her betrayal. Also worth noting she was my BIL first relationship/ girlfriend, so he has no other frame of reference.
They've also decided to go ahead with the wedding this year, 10 months after the affair came out. While I think it's far enough to stay together, I think going ahead with the wedding as planned is a joke - especially with it taking place in a catholic church.
While the rest of the family have totally forgiven and forgotten, my husband and I are really struggling to come to terms with it and treat her as family. My husbands family don't want it to be talked about, it is completely swept under the carpet now, but I havent directly spoken to my BIL or his fiancee since this came out (6 months ago).
At the request of my mother in law (who i greatly respect, she has helped me a lot with my DS) I did reach out to the girl involved, suggesting we meet and bury the hatchet. The reply was quite a rude and basically indicated they were angry at us, and that she was willing to accept me as family 'no matter what' (inferring I'd done something wrong??).
Since that exchange of messages there has been no contact, I'm avoiding family situations/ occasions where they'll be and visa versa.
I'm happy to continue with this, but with the wedding approaching i feel it is going to come to a head, as I don't want to attend and don't want my son to attend.
I would go out of respect for my BIL (who was a close childhood friend and how I met my husband), but as he hasn't spoken to me since this happened I feel that I have no relationship with the bride or groom, and it feels bizarre to think of going to their wedding when I'm not on speaking terms with them.
I still feel so angry at her and I feel devasted for my BIL, because he is such a lovely guy and I feel he is being duped. None of his close friends know the truth and I worry the only people he confinded in - his parents- were more worried about maintaining the status quo (as the wedding invites had gone out, they own a house together etc) then his self esteem and self worth.
As the family have moved on so quickly, I feel they think IABU to still hold a grudge and not let it go, I also know it will hurt my MIL and FIL to not have me at the wedding, more then anything because they wouldn't like their friends to think/know they was an issue/dispute in the family.
I know I'm taking the moral highground with nothing to really gain, but just can't move pass the fact that she did this to my BIL and also to my work friend - who has now ended her marriage of 10 years.
It seems wrong that on one side a marriage is over, but on the other its business as usual and the wedding planning is in full swing.
Had her cheating been a one off, or even a two-off thing, I wouldn't feel as strongly but it was such a prolonged affair, with meeting for sex 1-2 times a week in my BIL house, there was also a lot of bad mouthing of my BIL in the messages exchanged, and she was putting a lot of pressure on the man involved to get a solicitor and get a divorce.
I also find it weird that while my work friends marriage was in a bad place - they were having counselling - my BIL was unaware of any problem, and his fiancee seemed fine and very actively planning her wedding.
Another side note is my own brother, having cheated on his fiancee went ahead with his wedding and then split after 6 months - and still can't start divorce proceedings as haven't been married long enough. I wish I'd advised my brother to delay his wedding, but as he was the wrong-doer I guess I encouraged him (or at least didn't discourage hime) to make things right by going through with it (in the end it was his wife's choice to end it). I'm raising this as I have recent experience with how marrying of the back of infidelity is never a good idea!
Sorry for such a long post...I guess my question to you guys is AIBU to not forgive and forget, and AIBU to not attend wedding?

No, I don't think she should tell others about it as it would hurt her bil and goes agsonst his wishes. But from a 'moral' pov, I don't think she is under any obligation to lie or attend the wedding.
I do doubt that bil knows the full extent - I don't suppose anyone has told him that sil's text messages about him were so nasty or that she was having sex in their home twice a week. Or the extent to which she was pressuring om to divorce his wife. There's a difference between knowing something and seeing it in all its gory detail.

I think people try and get their lives back to normal as soon as possible once they've made the choice to stay and I think he's maybe not had sufficient time to process it all, so rushing into the wedding isn't the best idea. If the OP doesn't want to publicly endorse something she feels is wrong, that's her prerogative.

Bleurch, Arsenals, what a cringey post.. you know nothing as to whether BIL's marriage will fail or not - or whether SIL will cheat again.

You sound like one of those women (sorry, but they always are) who sit around gossiping and rubbing their thighs about any misery going on in somebody else's life.

If I were BIL I wouldn't have OP - or anybody like you - anywhere near me.

On the public endorsement, we agree, IWanna, OP - if she cannot keep her feelings neutral and behave as expected at a wedding - should not go. For the sake of everybody else at the wedding and particularly for the BIL whom she professes so much care and concern for.

Why wouldn't BIL want the OP anywhere near him?! She actually seems concerned for him, and her friend, which is more than can be said for his "fiancé".

So you have told all your friends! You watched revenge porn and you have plastered very identifying details on the Internet.

Your partners family have got past this, the bil presumably has got past this and made peace with his fiancée.

What on Earth are you hoping to get from this op? More drama? Have got fail print the story and identify your Family??

Get this thread pulled honestly and either go to the wedding with good grace or ‘be ill’ this is absolutkry none of your business.

watching revenge porn is hideous by the way and not sure it’s not a crime now.

Gosh. This is not your business. Not for you to forgive. There is no hatchet to bury. Saying so makes out she should be grovelling to everyone.

Agree LyingWitch there’s a touch of knitting around the guillotine in some posts.

Just leave them be to get on with their lives.

Sinister, why would he? He's made his (considered) decision and OP, not knowing anything about their private conversations, is treating him like an imbecile who cannot be trusted to know 'what's best for him'.

OP has had validation from ALL of her friends who've told her NOT to attend. I don't know why she considers that bias, it's not - it's sensible.

Ohmydayslove, I agree very much with your post, I think that is quite probably what OP is hoping for and that being the case, won't want the thread pulled.

and yes, the watching of the video made me feel sick and I think if the shit hits the fan, it will fly off in many directions.

I do think people are over egging the 'revenge porn' thing. OP saw a few seconds because the wife was illustrating to her that events were not exactly as they were being portrayed by sil. Not like she posted it on fb or anything!
Besides, if you make a sex tape and send it to a married affair partner, you run the risk of his wife finding it and showing it to people (whether legal or not). This is entirely a situation of sil's own making.

sorry but why the he'll should BIL go NC with family members because his fiancé cheated? Especially when those family members are going to have to be the ones to pick up the pieces when she does it again, not if. While I don't especially subscribe to the once a cheat always a cheat line, her sustained deviousness an attempts at getting the other man to leave his wife, then blaming it on BILs depression, plus dismissive attitude to OP, fiancé does not sound like a nice person, it sounds like someone who as got away with it and doesn't give a shit. As for revenge porn, come on! The op may have opened a link unknowingly, or had BIL shove phone in her face saying "look at this!" Before she could look away saw half second and it's burned into her brain. Stop blaming the OP for everything.

Sinister you and a few other posters are ascribing emotions and characteristics to people where you don't have that information. Why are you doing that? It doesn't bolster your post in any way, it just makes it look as if you're trying to 'pad out' what isn't there.

I've read the OP's posts - that's the only information here - and ignored her surmises because that's all they are. She's treating her BIL like an idiot and that's not ok. If OP cannot accept this wedding then she should stay away.

Regarding the revenge porn, it is now against the law and thank goodness. If you or somebody you loved had been caught up in this, you'd think differently I'm sure. Your dismissiveness on this topic makes me feel uneasy and question why you're so invested in propping up the OP.

I've gone exactly by the information the OP has given. If your trying to make assumptions about me and my view based on these please don't bother, I'm not biting, it's a sunny day and ironically there's a nice we'd on TV.

Back to the OP again I'd say go to the ceremony to keep the peace with the red of the family, especially for MIL but make excuses for the reception.

A nice wedding

OP DID NOT WATCH 'REVENGE PORN'

She saw clips of sex videos the SIL HAD MADE AND SENT HERSELF, TO HER AFFAIR PARTNER, OR THEM BOTH HAVING SEX.

OP's friend, the cheated on wife, FOUND THEM and showed either one or many of them to OP IN ORDER TO DISPROVE SIL STORY THAT THEY HAD NOT EVEN MET/KISSED.

The sex videos were not circulated or shown as 'revenge'. They were shown by distraught WIFE to her FRIEND to prove that it was physical.

'Revenge porn' is when someone distributes pornographic material in order to humiliate or attack someone, ie the person featured.

THE ONLY PERSON SENDING PORN AROUND BY PHONE IS THE STUPID CHEATING SIL, OF HERSELF.

FizzyGreenWater - the wife shouldn’t of showed ANYONE the video. It wasn’t hers to show her friend or friends.

Sinister your last but one post is full of assumptions. I'm very happy not to get into a tit-for-tat posting with you but it's there to see.

Non of us knows what's really happened here - and the OP only knows what she's been told or seen - she wasn't party to the conversations between BIL and his fiancée. BIL wants to marry his fiancée and that's known. What else is there to say?

As you say, it's a nice day and I need to get to the post office before it shuts. Enjoy the wedding on tv, I'd like to see the dress so I'll catch the highlights.

I find cheating absolutely abhorrent and I would find it difficult to attend the wedding of someone who I knew had cheated. But I would go. I would plaster a smile on my face and make nice for the sake of my family in your position.

Just keep your fingers crossed that this affair was a one off thing and that your BIL and SIL are truly happy. If they are not and it crumbles then be there for your BIL without an I told you so. There isn't much else you can do unfortunately.

Happiness, agreed.

No-one knows why the cheated on wife showed the video. We don`t actually know much, we are being told one side of the story. ( Yes I know that is always the case here). If any one has a scrap of thought for the injured parties then they should shut up and let the people involved get on with their lives as they choose, stop being so high and mighty and get over themselves. I've been to plenty of weddings where the couple seemed very happy and it's all been over before the cake has been eaten and others which have lasted despite some pretty reprehensible behaviour. Shall we let it go now?

@FizzyGreenWater Calm down child😂

The ex wife distributed a sexual video of other people without their consent

She showed op a clip - not forwarded it. She showed OP to prove the video existed. Not out of revenge but to prove the truth (that it wasn't just chat)

And at the time she was presumably the wife, not ex wife. Maybe some posters vould think about how horrific all this is for her, rather than worrying about the legal rights of the woman who made and sent that video in the first place.

I'm loving the support that everyone is giving to someone who had AN AFFAIR.. it's very rare to see such behaviour celebrated on Mumsnet... this must be a first...