Do I say something?

[wonderingwonderer]

I’ll begin by saying that I am part of a close family. I’m really lucky to get on very well with my siblings, and their partners (well one of..)
My older brother is in, what I believe to be, a coercively controlling relationship. She’s succeeded in isolating him from the rest of the family - and there was a big drama last year which allowed her a reason to hate us all. I know that there are two sides to every story - but just assume that this is a toxic and coercive relationship. What do I do?
I know that advice is generally to accept the choices that siblings make - and to expect them to choose their partner over you. I 100% agree with this in principle, but what if the relationship is abusive?
My DH says I just need to step back, make it clear I will always be there for him and let him make his choice.
This just feels so wrong. I feel like I am watching him stepping off a cliff.
My other sibling and partner feel as I do - but are also unsure of what to do now.

Your DH is right

Can I ask if the answer would be the same if it was my sister and her partner?

Don’t step back. It’s one of my own biggest regrets.

It's so hard as what can you do though? Have you spoken it him about it at all?

I know it’s hard. But losing your brother forever because he can’t suffer at her hands any longer is harder than anything.

Can you give examples of why you believe he is being coercively controlled?

I think it's really difficult to do anything. He's an adult and if he doesn't want to leave, challenge his DP or whatever, then there really isn't anything you can do.

My friend had huge worries over her DD and a wicked DP but she was completely under his spell. She didn't listen to her Mum, sister or friends. They just had to wait it out and thankfully, she came to her senses and left him.

Those who say you can't step back, I'm wondering what could you do? It's kind of like an addiction - you have to want to be cured. Let him know you love him and are there for him.

Yes - accusing him of behaviour she exhibits and gaslighting him.
Restricting him from speaking to / seeing friends and family
Obsessively texting / calling if he is not with her or if he is working
Telling him he is worthless, stupid - that she can’t believe she is with him. This has really really affected him
Verbal and physical abuse
Not letting him sleep - especially if he has something important in the morning.
Silent treatment
Demanding ‘total honesty’ which basically means she gets to go through his phone (he has never and would never cheat)
Bringing up every supposed misdemeanour in every disagreement.
Last year we found out how bad it was and encouraged him to leave - she now hates all of us and is demanding that we apologise
to her before she will speak to us.
They have also had joint counselling, which I now realise was a mistake as the therapist didn’t know about the abuse and therefore he felt that her view of him was validated.
Honestly it’s such a mess and he was so hesitant to tell us what was happening - and now it’s worse as he’s isolated from us out of her demanding ‘honestly and loyalty’ from him.

There’s nothing you CAN do though, other than keep communication channels open.

I do find myself wondering about this large, close family that gave her a reason to hate you all though…

I’ve explained. He told us the situation and we encouraged him to leave.

Try your best to keep in contact with your brother even if it's just texts to say how are you etc. Would you be able to meet up for a coffee or a walk? Don't bring up his relationship at all unless he does. Just tell him you love him and you're always there if he needs anything. You can't persuade him to leave, it has to come from him. She will try to isolate him so prioritise keeping in touch with him if you can.