Brother is a cheater- do I tell?

[baddabingbongbang]

Name changed for this just in case.
My brother is a serial cheat. He's cheated physically and emotionally with multiple women including close friends of his over the course of about 5 years. He and his girlfriend are both 24 and are planning on buying a house soon. He's treated her appallingly and she deserves so much better than this. He's told my parents that every time she gets close to finding out, he lies and twists the situation to save his own skin, calling her controlling, threatening to leave her etc until she backs down and trusts him.

I'm really torn whether I should tell her. Everyone in the family knows what he's like but she appears none the wiser. We'd all hoped he'd be found out organically before things got too serious between them but this has been going on for years now and they're on the brink of a big commitment to each other.
Any experiences or advice would be welcome.

Oh OP that is a really tricky one. Obviously you love your brother but despise his behaviour.

She is going to find out one day and if kids are involved the fallout will be a lot worse.

Is your brother aware how the whole family feels about his behaviour? As a family can you all tell him his behaviour is despicable and tell him if he doesn't tell her, the whole family has decided collectively they will tell her, with you being spokesperson?

This way, it gives him an option of being truthful at long last, and if the whole family, rather than you stands up to him, he is more likely to see the error of his ways?

of course you should.

Tell her. She’s 24, she’s young and could move on and do great things and meet great people without an arsehole dragging her down

This is one of those occasions where I think you should dry snitch.

By that I mean if you tell someone who knows her closely, the information you want to get to her, will reach her from someone who is trusted and who she has to listen to.

I think CareBear50 above has the best approach by far (why is he telling your family this and not expecting some sort of reaction?!) but I thought I'd offer another in case useful.

What a despicable person your brother is!

Why on earth do your parents tolerate this and enable this abuse!?

I’d tell, tell her to run for the hills and not look back.

Yep. Two things... call him out and condemn his behaviour to his face. Make sure she finds out via a trusted source.

Would you want to know, @baddabingbongbang, in her situation?

Absolutely I would tell her. I couldn't live knowing I'd done nothing whilst her life was ruined

Thank you for the responses so far.
I would definitely want to know but it's hard when it's my brother and his relationship.

@JuniperFather that's a really good shout but how do I figure out who to give the information to without it being obvious it was me?

I’m definitely for telling her and as soon as possible.

I was with someone who repeatedly cheated on me and I didn’t know. I’m still a bit pissed off about the years I wasted with him so really would of appreciated someone telling me earlier than when I did find out. The pain and hurt will be the same but at least it limits the wasted time.

Your brother has no remorse for his behaviour and is apparently quite happy to share that he’s cheating with everyone (but her). It’s not big it’s not clever so perhaps it’s time he learnt that most people wouldn’t find his behaviour acceptable.

She's 24 years old.

Tell her, 100%

Very tricky. I would tell her, but be prepared for your relationship with your brother to suffer and/or end.

Option 1 - Tell her now - risk upset and family drama, and her maybe not believing you, but IMO morally correct and at least when it all comes out later she can't say you didn't warn her or treat her like a fool

Option 2 - Do not tell her now - more significant upset and family drama, and her feeling even more betrayed than if you told her previously.

I would absolutely tell her and I wouldn't give two fucks if he knew it was me.

Save her from wasting any more years with a manipulative and emotionally abusive liar.

He's not only cheating but also gaslighting her and being emotionally abusive. I can't understand how your parents are ignoring this.

What do your parents say? What are they telling you?

Yeah you should tell her, or tell one of her family so it gets back to her

Probably not the best thing to do but send her the information anonymously and with any proof if you don't want to damage the relationship with your brother.

Very hard situation, I would tell her. Mainly because they are going to buy a house together, be prepared for him to go mad at you.

My parents aren't happy with him for his behaviour in the slightest and have told him over and over to tell his girlfriend. However, they think as it's his relationship, it should be down to him to tell her or failing that, for karma to just come naturally.

If it were me I would want to know and would be upset if I found out you knew but didn't tell me. Do imo you should tell her.

Sounds like she knows anyway and is suspending belief in her own instincts.

I’d keep out if it.

Can't stand it when parents dont hold their adult children accountable for their behaviour. It just reinforces the fact that the child doesnt need to give a shit about how they treat people and can do what they like because they are an adult, regardless of the affect on other people's lives.

Tell her.

@baddabingbongbang just read you last message...good!

Can you tell him that if he doesn’t tell her then you will? Will you parents back you up? He can’t cut all of you off if you’re singing from the same hymn sheet...