I have had what I think you are describing for my whole adult life, and I am middle aged now. I think of it as an absence of lust, and I have wondered if it is part of my AS, or just my own bizzare trait. I have not seen anyone on this site write of it, and I actually hope you do NOT have the same trait I have, because if you do, I have to tell you that it doesn't go away. I remained a virgin for many years, not because I couldn't attract a woman, but because when it came to sex, I found the actual presence of a woman a distraction. My fantasies were ABOUT women, but having a real woman right in front of me, or next to me, did nothing to arouse me. This was not 'performance anxiety', though after some unsuccessful encounters, that later entered into it. It was in its pure sense a simple indifference to the visual and tactile sensations that should have aroused me. And while I had a psychological desire to copulate, I had no physical desire to do it--if I hadn't learned from others where I was supposed to stick that thing, it never would have occurred to me what to do with it. Eventually I literally taught myself to ignore the presence of my partner and concentrate on what was in my head. Alcohol helped me do this--it seemed to help me to ignore the physical presence of another person and to draw into my own head, which was the only place I could find arousal. I have overcome all this with great difficulty and am now married. But to this day, having intercourse is something I "pull off", and not really something I enjoy.