Hi Jama,

It has to feel sad and helpless that you’re son is taking sides. We have a good article on drama triangles the best position to put yourself is in the middle of the triangle by taking neither side.
Escaping Conflict and the Karpman Drama TriangleI’d suggest to wait and don’t ask him if his W is a pwBPD there’s a potential there that it will further escalate things this might be difficult to hear but it might satisfy your curiosity you know that she takes meds to treat a mental illness. That’s a positive that she’s helping herself.
There are a lot of members here including me that have a pwBPD in their lives that is not diagnosed. We can’t diagnose because only a professional can do that! What we can look at are BPD traits and how we respond and react to to behaviours from a pwBPD.
Triangulation is not synonymous with BPD it’s all around us and not all triangulation is bad triangulation. BPD is a persecution complex if you ask your son there’s a chance that he’s going to rescue his wife and you’re cast in the role of persecutor ( bad guy ) As I mentiones earlier the best position for you is in the middle of the triangle.
Aside from the meds can you share some behaviours?