Once by mistake I got on the Metro in Washington DC right after a charter school had let out. Every seat in the train was filled with African-American teenagers. This was shortly after I had started estrogen, not long enough for it to have had any effect on my appearance.
When I stepped on and stood in the middle of the car, there was silence around me and furtive whispers for a couple seconds. Then one of the girls burst out very loud, "Oh NO!!!" and immediately the entire train car was filled with the loud, raucous laughter and jeers of the teenagers. They continued laughing at me for as long as I stood there. I stayed calm and showed no reaction. Meanwhile, I began to suspect I'd gotten on the wrong train, so I tried looking at the route map on the wall. The girl sitting in front of it ostentatiously leaned away from it until she was horizontal as if to keep away from my line of sight. I paid no attention to the continuing loud laughter and exited at the next stop with calm dignity. As I stepped out of the car, behind my back I heard a young man shout "->-bleeped-<-IN ->-bleeped-<-GOT!"