I was 17, and (believe it or not) a virgin. I had always been a shy kid and was raised in a family that didn't discuss sex. I knew how to masturbate, and secretly did so a lot. Beyond that, I had no sexual knowledge or experience.
I'm not sure why I was downtown, but it happened that I was going home during the rush hour. It was hotter than the devil and there were a million people on the platform waiting for the train. When it pulled in, everyone started cramming into the nearest car. I got in, reached for a pole, and held on the best I could. I was standing next to an older woman. She smiled at me as people jammed against us from all sides. I grinned back and just held on.
When the train started, everyone swayed back and forth as the train rocked along the tracks. I was swaying against the woman and could feel myself getting an erection. I was mortified. At the next station, more people jammed into the car. When we started to roll again, I could feel my cock rubbing against soft flesh.
It took quite a while before I realized that the lady was stroking me, on purpose. She was holding my cock through my shorts and gently moving it against her leg. I nearly flipped. I'd never had anything feel so good, but I was scared to death. I remember thinking she'd 'find out' it was me. How stupid. I didn't know what to do. Then, I realized she was smiling at me. My face must have been dead white, I was so scared.
After I looked at her and she smiled at me, she started to stroke me up and down, giving me a proper hand job. My cock had been hanging down. When it got hard, it was straining against the leg of my shorts. She had a very gentle hold on it, and was rubbing it up and down and looking right in my eyes and smiling at me. I was so excited I couldn't control myself. I thrust my hips forward trying push my cock further into her hand. As I did, she started stroking me really fast. In just a very few seconds, much too quickly, I shot what must have been the most enormous load I've ever had. My legs were so weak I'd have fallen down if it weren't for all the people jammed up against us.
As I caught my breath, she slowed her hand down and caressed and cuddled my cock. Then, she put her arm around me and hugged me. I wanted to hold her, but was too shy. She held me for several more stops. Then, without saying anything, she kissed my cheek and squeezed her way off the train.
What a wonderful person she was. I've dreamed about her (and beat my meat thinking about all the things I'd have liked to have done on that incredible day) every since.