I was dressed in a short, tight dress during the summer in London. I won't lie. I have an outrageously good ass. Anyway, my friend and I managed to fit into the train despite its extreme crowding. It was packed full with people, like sardines. The guy behind me pushed his hips and his penis into the back of my ass in a very slow sexual way. I could feel his erection. I froze, started breathing heavily, and gently pushed my ass back against him because it turned me on so much. Hoped the ride take longer, because my pussy was dripping... I was acting really outraged when I told my friend what had happened after we got off the train, and she said, "You liked it didn't you?"