I am not sure that there is a way for the partner to know if they have been with a Narcissist. But I do know my therapist began to come to that conclusion after ony a few sessions... I had no idea mine was... My Thrapist started to peel away some of the dirt covering my wounds and came to the conclusion that not only did I spent the last ten years with an NPD (narcissictic personality disorder) female, but she was verbally abusive on top of it all... I moved out (of course she never asked me to, but it was damned cold and miserable at home) 5 months ago and have been scrambling to regain my balance. After much talking and writing (talking that my partner and I never did) I now see the signs of the bad relationship. if you are aware enough that you feel something is very lopsided in the relationship, I think that is one of the biggest clues. example: my partner's daughter was no angel, but my daughter (not a perfect kid) could do no right, and hers was just "working on it" my friends were just barely OK but hers were more important. We spent almost every holiday at her family's, but I felt it was an imposition to invite my daughter. It was just convenience that most of my family lived out of state... If you think you may be with an NPD, then the first thing you feel fading is the 'you' part of the relationship... Just pay attention to the Toby Keith Song "I wanna talk about me" and see if you can identify with what he is saying... If you search hard enough, you should be able to interperate what the answer will be... == How you feel (and behave) could be a red flag that you have been with a narcissist. Things like an odd feeling all along something was not right. Or that you will never be good enough. You can also get vibes from him. He wants to get under you skin, find out everything about you. You feel exposed and exploited. Used, deceived and tricked. You might start feeling irritable, anxious and suspicous of everyone. I was told by a PhD who counseled my ex-fiance' and I as a couple, and my ex alone that he was more than likely a Narcissist. Because my ex hadn't seen the PhD long enough - the PhD wasn't able to do an official diagnosis, but he was the one who brought it to my attention. I didn't know what it was before. Additionally, a different PhD I saw thought he was an N also, based on what I shared. I have had a hard time admitting this. Knowing how the victim feels helps to create a much clearer picture. What you have both said above 'really' resonates with my experience, especially the 'fading' of yourself, lopsidedness, and the feeling that 'something isn't right'. I gathered as much information as I could before canceling the wedding (8 weeks prior). It was the most difficult decision of my life. I suppose I am continually seeking information to confirm I made the right decision. Thanks...