U answered ur own question. IF there truly IS a sense of internal struggling wrt your gender identification that is ameliorated when you allow yourself free expression as the female you feel yourself to be, then I would say no, it is not simple narcissism. Only u know that. If on the other hand its just something u like to do for, say, sexual reasons, then it falls more in the domain of "recreational" sexual activity and - IMHO - it would be insane to lose a gorgeous woman over THAT? The question u have to ask is, if u had to make a choice, between indulging ur desire (or need) to dress, act and be a woman or not in order to preserve ur relationship with this woman, which way would you choose? How deep is your love?