Great question. In general, Narcissistic PD folks tend to do a few things that are rather unique to that classification. Here are the ones to be on the lookout for:
(1) Always has to be the center of attention. Typically, grandiose story telling or emotional hi-jacking happen to ensure that they remain the center of attention. Lying to create an "ideal self" is common - and they are SKILLED liars!
(2) If they feel criticized in ANY way - regardless of how small/benign the comment is - they will launch an all-out attack on the person whom they perceive to be criticizing them. In other words, they do not take feedback well - in fact, their reaction is typically WAY more harsh than the situation calls for.
(3) They will always "one up" you so that they can appear to be the most interesting/intelligent/gifted/best/ etc. in the room. They will not be able to tolerate being considered as "second best," regardless of the scenario in question.
(4) They will have a difficult time mustering empathy for people around them.
(5) And finally, despite the notion that Narcissism is having an overly high opinion of one's self, quite the opposite is true. A true narcissist has grown up in an environment that did not help to foster an internal sense of "I'm okay." So, the narcissist now has the chore of pulling "YOU ARE GREAT" from everyone around them. Unless they are the center of attention and adored by all who come into contact with them, they will feel empty and worthless inside.
I hope that helped. If your lover is indeed a narcissist, be very careful. To him, you are merely a means to an end rather than a real, 3-dimensional person with needs and feelings. And be wary of compliments, intimate moments, etc... they will be "put on" by the narcissist who has learned how to "act" in order to get his needs met. I do wish you well. If you are satisfied with the response, please hit "Accept." That is the only way I can receive credit for my answer. Thanks-