brother deteriorating health due to BPD partner (my SIL)

[chain123]

Hello,
This is my first however I've been reading posts for awhile now and have found a lot of the info relatable.
My SIL has undiagnosed BPD. Her and my brother are married with 2 kids (one is his stepson, her son from previous marriage).
She lives away from her home country and in his home country. Her family are not around but my brothers (us) are.
She does not allow my parents to see their grandkids. This has been the case since before they ever met, nothing obvious has triggered it. She accuses my mother of trying to steal the kids from her and makes up a lot of lies about her. My mother seems to be her biggest target.
My mother & father have not seen their grandkidds in over 2 years. My brother seems to have accepted this for an easy life, but my main concern and the reason for this post, is that we are seeing a huge deterioration in my brothers health, both mental & physical. It seems he has reached his limits but he feels he has no escape. He is being controlled and manipulated, works 70 hours a week to support them all as his BPD partner wont get a job, and the worst part is that she speaks to the kids in a language he cannot understand so he does not know what is going on in his own home. He has never once been in a room alone with his own child, BPD partner wont allow it.
We feel he is not setting the correct boundaries and that this has been going on for too long (7 years). He visits us a few times a year only, never with the kids. We are afraid if we are harsh with him that he will retreat from us more and more. We really don't know what to do.

[TelHill]

Welcome to the forum, chain123.

That is a very tough situation for your family and brother. My dBPD mother has had a fear of being abandoned, including me suddenly dying, as far back as I can remember.

That includes being dumped as an important person in another loved one's life. My mom is from overseas and most of her family stayed behind. As I grew up, my mother told me her parents were dead. It was partially true. (This was when the only communication was through letter or telegraph.) She was in tears one day and another relative offered her sympathy on the death of her mother.  There were other instances like this one when her twin sister and her children immigrated to this country. I had no idea they existed before then despite being a typical nosy kid asking questions all the time about her family. She also told me my dad wanted to marry me and she would go away. She was too old and he didn't like her.    I was four and she was 34. I assume she had to be top dog. The only alternative in the eyes of the bpd was being abandoned and forgotten by them forever.  It's very black and white thinking and very childlike.

I believe the same rigid/black & white thinking is taking place with your SIL. It's not going to resolve this terrible situation for your brother or the rest of your family. I'm hoping it may help you guys knowing this is typical bpd behavior.

You can continue to communicate with your brother as much as you are able to show him you are there for him. The impetus for boundary setting has to come from him alone unfortunately. You are smart not to rock the boat. It would set off retaliation from your bpd SIL.

It might help to seek therapy with someone who specializes in personality disorders for continued suggestions and support.