Anything can start out solely sexual and become an emotional attachment over time. When you're thinking of yourself as a woman in your fantasies for long periods of time and the reality is that your body is not at all what you fantasize about, you start to become so fixated on patching up the incongruence between your real body and the body you have in your fantasies. I've seen it myself. I went from "whatever" few years ago to "Oh my God, I want her dress and I want to be her". I think this is what separates the "Cis" AGP from the transexual AGP, the "Cis" AGP will form no attachment to the idea of being a woman and it'll just be a simple fap fantasy. the transexual AGP will welcome these feelings and believe he/she was supposed to be a man/woman with increased feelings over time, so even though it may have started out only sexual, the fetish takes on a life of its own without its host even realizing before it's too late