I have no idea whether or not my ex has ever been formally diagnosed, but BPD is the only thing that's consistent with his behavior patterns. He's been in and out of therapy since childhood and would say vague things at times, like "I can understand why you'd leave me. Not everyone can handle this." He'd have moments of clarity regarding his rage: "When you don't validate my feelings, it makes me very angry." I asked him directly a couple months after the explosions started whether he'd had similar problems with exes in the past and he said no, but then told a mutual friend after the breakup, "I've known for a long time that I have an anger problem, but this relationship has shown me that I need to do something about it." Not sure what the real story is, as he seems to bend or obscure the truth on a regular basis. He's in therapy, I'm in therapy, we're NC now. It is what it is.

I ask this question because I had no idea what BPD was before he and I broke up. Now that I have more information I really wish I had known about it during the relationship. As I don't know whether he's received a diagnosis, he may be entirely unaware of BPD as well and therefore it wouldn't have made a difference if I'd known about the disorder, but I do wonder at times if he knew and decided not to tell me.

If you have BPD, do you tell your SO once things have gotten serious? Why or why not? Please help me understand how you handle this choice and why.