Although it is sad your circumstances brought you here, you are welcome to benefit from our collective wisdom, wide membership, time-tested strategies and more.
PS he has 2 lovely sisters who absolutely adore him because he will do anything for them & he pays for holidays etc for them. They have NEVER seen this other side to him, so assume obviously that I'm the problem in our marriage (I'm the one in therapy so a fair assumption!). He almost appears to have a fake persona when he's with them-is this a thing with BPD?
BPD is a disorder most impacting to close relationships. Those on the periphery - such as his sisters - generally don't get the full intensity of the poor behaviors and cycling AKA roller coaster. And the sisters don't see what he does in private scenarios such as at home behind closed doors and probably too when riding in vehicles. He's grown accustomed to venting on you - letting his hair down, so to speak. Since you've been with him for so long he likely doesn't care about how he appears in your presence and expects the long
obligated relationship makes you less likely to leave him or speak up about what he does when alone with you.
We often mention BPD FOG - Fear, Obligation, Guilt.
If you do try to speak with his sisters, likely he would Deny, Blame and Shift Blame. It would become "he said, she said" which courts typically ignore as hearsay. Before you think to speak with the sisters, do you have any proof of what life is like with him? I divorced many years ago, long before the age of today's cell phones so I used digital audio recorders to record my then-spouse's tirades, blamefests and worse. (I did also make some camcorder videos but she discovered the tape and ripped it into little pieces.) So I knew much of what I reported was documented with recordings or sometimes witnesses.
