I remember doing that when I was 10 or so. At school, when we went to the swimming pool we always had to share a tiny dressing room with someone. I always managed to end up with the same boy, a close friend of mine. When both totally undressed, I always started acting silly, pulling my tiny dick backwards between my balls so I ended up with this nice bald boy pussy, shaking my ass and talking softly 'look I'm a guuuurl'. Nothing happened but that's the earliest I recall for discovering my inner slut