My dad is an NPD. His big thing was to get sick when we got sick. Example. I was 10 and got pneumonia, very bad, had to go to the emergency room when I passed out in a movie theater from fever. My sister and I shared a room and we had twin beds. As soon as I was well enough to function, dad got "sick", and took to my sisters bed beside me. Being the oldest, I had to get up and tend him, which resulted in my having a relapse. If one of us was sick, he would get sick. This has resulted over the years in my refusing to be sick.
One of the big running jokes when I was diagnosed with fibroids is that dad must have gone crazy, as HE couldn't get a hysterectomy! The other running joke was that dad wanted to get cancer, but he would get scared of dying, so he would get "almost cancer". This was funny till my sister got breast cancer. Now we tell her that she really shouldn't try so hard to get his approval!
Dad has always done what others have done. The mirror theory is an apt one. Dad has been serving on a committee for a veterans thing. As time has gone by, he has told people that he has been in the Korean war, the Vietnam war, and has flown secret missions, and was at the fall of Saigon. Let me state that this disturbs me terribly - he really has no idea how crass and awful that is and what a mockery it makes for those who really were there. Because he is "ill" with his NPD, he will say these things. He MUST have approval and validation, at all costs. It is a tragedy. I have witnessed him telling people these things, and I am horror-struck that it has gone to this. While I was growing up I watched him constantly fabricate and grow himself to be better than what he is. The sad thing, too, is that if you were to look at his real accomplishments, you would be impressed. Just the things that he has really done have merit. He is talented, dynamic and ill.
I would stand behind the idea that your boyfriend does not know that he is mirroring. You cannot fix it, and I wouldn't try. He sounds hollow inside, as NPDs are, they are only shells. SS describes it as being born without a soul, and that is an apt statement. So he can only mirror to have an identity. I would say that yes, this is NPD as well. When he looks at his reflection in the pool, he sees the things that you have done and calls them his own. He sees himself in what you do and say. See? On drirene.com there is a lot of information on NPD - I think it is in the abusers section, check it out. She has excerpts from Malignant Self-Love, one of the best books on NPD.
Soulful, if you read this, it has been a year now since I last talked to dad. Sometimes I feel guilty, that I left this old man all alone, but deep down I know that it is a loving thing to do for myself mostly, but for him, too. If I continued to allow him his abusive conversation and needy behavior with me, then he would have no opportunity to change. It had been my hope, of course, that my silence would trigger some epiphany in him, and that he would seek some help, but no. I don't see that happening. You have been a big help off and on for me as I dealt with all the feelings that have surfaced. I am healing, albeit slowly. One of the hardest things about loving an NPD is the wishing that they could see their part. But that is absolute futility to even dream of it. The sorrow is in accepting the futility and moving on, I hate that dad thinks I don't love him. My only consolation is the idea that when he dies he will know all things, and that he will know then that I am not cruel, that I love him...