BPD crisis: BPD partner is abusive towards his mom, he refuses help

[Speed]

I feel very sad because my partner, who has BPD, has the false belief that his mother is the one who has a mental illness and needs help.  He calls his mother a psychopath who has no emotions and feelings towards other people.  He accuses his mother of stealing money from him, as he believes he and his mom each owns 50% of the condo they live in.  This is not true -- mom holds 100% ownership of the property.  What I think happened was that sometime in the last 20 years, mom told him that he would receive 50% ownership of the condo after she dies.  Somehow, in his brain, he thinks he's already entitled to the 50% and he thinks mom is now trying to take it away.  

My partner has been abusive to his mom over the years, mostly verbal abuse but physical abuse has also occurred.  I learned from his mom that he has pushed her down once before.  Right now, mom has left and is living elsewhere with her sister, which I feel is a good thing because she is protected from any potential harm.  Meanwhile, my partner continues to believe mom has this plan of taking away his 50%, and he says he is going to find a lawyer or police to arrest mom.  

I was reading a lot of information online about how to communicate with someone who has BPD.  I can usually keep calm in my conversation with him, but there's no way I can change his beliefs.  He has all the classic symptoms of BPD, but sadly he denies having mental issues, refuses help, and continues to think his mom and me have mental issues, are stressing him out, and he feels he needs to pull away from us so he can have a happier life.  

Just wanted to share my story with the BPD family.

Thank you.

[RolandOfEld]

Hi Speed and welcome!  Thank you for sharing your story.

First I want to focus on the abuse issue since everyone's safety is foremost. Has your partner ever been physically abusive of you, or is it something you fear may happen? Besides the gaslighting and withdrawing, how else do his BPD traits manifest in your own relationship with him?
 
~ROE

[Turkish]

I'm glad that his mom is safe and this sounds like an elder abuse issue which could be addressed by Adult Protective Services (physical and possible financial abuse). This is something you might not want to step into to solve as this is between them. Do you feel safe?

Turkish