Should I tell his fiance he cheated

[Hopelessnaive]

I met a guy at work a little over 18 months ago. We became friends straight away, within 2 months it turned to more than friendship. We talked all day everyday, spent every minute we could with each other. I really fell for him. He always said he wasn't looking for anything serious at the moment and didn't want anyone at work to find out as it would make things awkward for both of us. I never pushed him, but I hoped that one day he would change his mind. I knew he was the one I wanted to be with.

Only it turns out I was a complete idiot. Not only does he have a long term girlfriend (around 10 year relationship) but they've also recently got engaged. No wonder he wasn't looking for anything serious.

I am absolutely devastated. Ive barely stopped crying since I found out. He's now ghosting me as he knows I know. Im not even worthy of an apology or an explanation. I obviously never meant anything to him.

He doesn't use any kind of social media, or I'm sure I'd have found out sooner. But I've found out who his fiance is through other colleagues, and after a little searching I've found her on Instagram, so I could send her a message. I just don't know what to do. Do I send her a message and tell her he's been cheating on her for over a year, or do I just let it go and say nothing and try to forget him?
Part of me is angry and wants to spoil his relationship to hurt him. Part of me thinks she deserves to know, especially before marrying him, and part of me thinks I'd just get turned into the bad guy and maybe she'd forgive him.

YABU- don't message her.
YANBU- message her and tell her everything

Men like this leave such a trail of destruction behind them because their victims take on the shame of their actions. First I would protect myself by getting a new job. You need to do that, he will prevent you ever getting anywhere in your current place of work now, so accept that and move on. Once Id done that Id be making sure HR knew, maybe in an exist interview, how my older much more senior 'mentor' was behaving with junior employees.

Once Id left, I would also be sending a message with evidence to his fiancé. Saying to her that I was extremely upset I had been involved in a cheating situation I had no idea existed. And that I could not in good conscience say nothing.

Then I would move on without a a second thought or look back, knowing I had done what I thought was right. And hopefully contributed a little towards protecting others from this bell end, who thinks getting his dick wet is more important than hurting the people he supposedly cares about.

I would tell her. But I’d make sure I was doing it because she needs to know the truth about him before marrying him, not just to get revenge on him, no matter how tempting that would be. Also she needs to get herself STI tested. Bet this isn’t the first time he’s done something like this, he sounds pretty skilled at it.

If she hasn’t sussed after 10years that he is a piece of shit on her shoes then there isn’t any point telling her because she won’t believe you. OP you won’t have been the first, you probably won’t be the last.

What you need to do is look after yourself.

I would personally start looking for alternative employment. Although none of this is your fault and you shouldn't have to move, you are now stuck between a rock and a hard place. If you stay in your job and stay quiet, having to work alongside him after what has happened between you will be unbearable. Being heartbroken and being forced to see him every day along with hearing news about his upcoming wedding sounds horrific.

Objectively telling the partner being cheated on is the right thing to do and in most circumstances I would be advising this. However; this could have disastrous implications on your career and working environment. It isn't worth sabotaging your peace at your place of work where you spend a great proportion of your time.

There is a high likelihood that he will retaliate and seek revenge from you telling his partner; he could also frame you as a psycho trying to sabotage his relationship to other colleagues. You don't want your colleagues viewing you as a Baby Reindeer type character or maliciously trying to destroy a happy couple. It isn't worth risking your well-being, peace and reputation in this circumstance for the sake of seeking justice for a woman you have never met. Put yourself first, there almost certainly will be other women and she will find out about his true nature eventually.

Oh no! I did not rtft and didn't know he was a mentor. That puts a whole different slant on things. Instead of telling his fiancé op definitely needs to tell HR. Listen to @GrannyJJ whose advice is spot on. What a turd he is.

OP was deceived. If her motive is revenge based on being deceived, why is that such a bad thing? The fall out isn't her responsibility.

Why are women not allowed to stand up for themselves?

If I were her, I’d definitely want to know.
Please tell her.
No need for any ‘attitude’ or sordid details - just the cold, bare facts.

I don't think you can win either way.

He abused his position.
He deceived you.

You're vulnerable at work - he could so easily turn this against you.

Tell her and he'll do the whole 'woman scorned' routine.

You can only put yourself first here. If you feel strongly about telling her, then be prepared to look for another job.

I expect she will find out soon enough - there will be someone else along the way.

How will she benefit? She’ll be worse off. If it was me I’d find a new job and walk away without a backward glance. Let karma take care of it.

I’ve been the cheated on wife. Transpired lots of people knew. While I sometimes wish people had told me, I also had a baby at the time and the cheating had occurred through our entire marriage so it was an absolute lie, all of it. You want revenge, I get it, but her whole life is going to explode in ways you can’t possibly imagine. I’m 11 years on and I don’t think I’ll ever quite get over that betrayal. It has changed me as a person. I have chosen to remain single as I don’t trust my own judgement any longer. So think carefully about wreaking havoc on her life. I am not for a moment saying he should get away with it, he shouldn’t, and eventually he will be found out. They always are. However, don’t do this out of
bitterness because it’s you swallowing the poison hoping somebody else will die.

If you feel you have to tell her I’d make a throwaway anon account and just say the bare minimum. He’s going to know it’s you. I’d also make sure I was in a new job. I’m sorry this happened to you. Some men are fucking foul.

The fact this lowlife expects OP to stay silent is a big red flag. That's not on, he's controlling the narrative.

As regards what benefit it will give OP telling the truth. If, as I mentioned earlier, OP handles this with HR firstly and protects herself then work should not be the main issue. After that, she's simply telling the truth. Why does OP have to tie herself up in knots keeping her head down? What does that achieve?

OP still has to heal her heart, in her own way and I agree, revenge alone won't help. If this is more than revenge, if it's about saying what happened, holding her head high, then more power to OP and I think she'd be dead right.

Remember, it’s not YOU hurting her by telling her. HE is the one who is hurting her. You’re just the messenger.

The fact that you've decided someone came on looking for advice about a situation they made up says everything about you and nothing about OP.

Who do you think you are barging in here with accusations and insults?

I sincerely hope with everything else she has going on that she doesn't waste her energy defending herself to you.

This is so naive. Of course work will be an issue. Whose side do you think HR will take and whose career do you think will be blighted? I’ll give you a clue - he’ll emerge smelling of roses.

I was in the same situation once with a senior work colleague. I had absolutely no idea. We were engaged and going to sign a lease for a house together or so i thought. I told the fiancée. Her family then proceeded to hound me if they saw me when I was out (I didn't know who they were so I couldn't avoid them at first but they sure as hell knew who I was) and i ended up needing to move house. They still got married which is their deal but be careful if you do say anything. It might not go how you think.

You could make it an HR thing, and she could find out that way. He was a mentor and in a position of power over you. He should never ever have used his position at work to get his end away. This smacks of all sorts of wrong and I doubt you’ll be the only one.

Don’t act. It will not give you anything. Be the bigger one and find your own peace.

There’s power dynamics at play here, and not just between OP and her ex. That they shouldn’t exist doesn’t mean that they don’t, and as such OP needs to consider the very real consequences she could find herself facing.

‘Doing the right thing’ could cost OP not just her job, but her entire career.

Terrible advice.
Revenge or poor motives aren’t relevant - neither change the situation for the fiancée.

If she knows or suspects it won’t be a shock.
I wouldn’t want to be marrying someone who was happy to be a player and hurting other women.

I agree that the motives don’t matter - who cares if it’s out of spite? - but she’s not “standing up for herself”.

Standing up for herself would be maybe going to HR.

What a reach, no one has insulted OP at all.

I really hope you tell her OP. If she’s engaged but with no kids with him, she can still get out pretty easily and you could be saving her from a lifetime of grief and being messed around.

you are very understandably angry, but the fact that you also get satisfaction from hurting him doesn’t mean it’s not the right thing to do for her. I’d send her one respectful, regretful note, with nothing graphic but enough screenshots to prove it, and say you thought she had the right to know.

Because she does. if she’s engaged chooses to ignore or not believe, that’s ok, she’s making her own choice.

OP could mess up her own career in the process and she has to work with this man every day if she chooses to stay in her current job. She doesn't know the woman, many men cheat and chances are she will find out sooner or later. She should put herself and her livelihood first, not some woman who she has never met just for the sake of a short-lived sense of justice.

I’d tell her sooner rather than later. They are engaged and the poor woman could end up pregnant by this dickhead. So sorry you’ve been treated like this, but you’re doing the right thing to warn her so she’s able to choose whether to ditch him or not.

Can you tell her anonymously, but still with proof?