How do you know for sure?

Hello! I was just wondering how someone gets diagnosed with NPD. My husband and I recently started going to marriage counseling (although he is not staying at home right now). I mentioned to the counselor that I think he might have NPD before we started going to her, but haven't mentioned it to her since. (We've only been to two sessions). I kind of want to know for sure. I understand that the things he does / says are not acceptable, but, if he doesn't Tweet