how do I help my Son with his DPD Wife?

[Summer Moon]

Our BPD symptomatic DIL was charming and thoughtful for 90% of the 3 years dating our Son. The idealization and devaluation behaviors were evident between our Son ad DIL during dating, but seemed to resolve with apologies and reconciliations. After a few years of marriage the DIL BPD behaviors seem to be growing more offensive and abusive toward my Son. Some significant BPD offensive behavior has been directed to my wife.

How do I introduce the possibility of DIL BPD diagnosis to my Son?

How do I prevent DIL BPD abusive behavior toward my wife the MIL?

[mother in law]

Hi. This sounds like our family  story and I too as the mil wore the abuse as well as my son. I don't really have any expert answers except to say support your wife and listen to her so she doesn't feel alone. It's very soul destroying for her and worrying as a mother. Good luck.