I am sorry you are dealing with this.
Before you say a word to your son about his wife, please stop- learn all you can about BPD and BPD romantic relationships.
I am not advising you to continue to feel as if you are living a lie. However, there are dynamics involved and IMHO, it would be good to pause and learn.
One example is the Karpman triangle. I was not aware of this or BPD relationship dynamics. My ( now deceased) father was co-dependent with my BPD mother. He was a strong rescuer and she took victim mode. I naively spoke up about her. I then became a "persecutor" on the triangle with them.
My mother sees people as "on her side" or "not her side". My father was then in the position where he had to choose, me or her. There was no choice to have both in his life. He chose her.
Because of these dynamics, you risk your son cutting you off from his family as he and his wife will perceive you as a threat. The rescuer -victim bond between them is very strong. Also assume that anything you say to your son, he will tell her as well. Rescuer-victim needs a persecutor- and you will provide this for them to bond over.
If you find it hard to believe that a son would cut off his mother- please believe it. Mother, sister, and even daughter. I didn't ever imagine my father would do that with me, as I thought we had a good relationship, but he did.
I know you love your son and want to speak your truth. It's good that you are here. There are ways to live your truth- without being confrontational and inadvertently adding fuel to the Karpman-Drama triangle.
