5:15. I had just jumped onto the train, boarding without even time to say goodbye to the friend who had walked me to the stop.

One more person can't hurt, I thought, wedging in, but apparently several other people had had the same thought. It was one of those days, however, where nobody seemed to mind the stuffiness. All the passengers were fresh, clean, and attractive, willing to forgive the cramped quarters, merely grateful to be alive another day, and that the day was done. Instead of complaining, the riders were joking. We could have been in a commercial for gum, or perhaps antibacterial soap, arm over arm, shoulder to shoulder, smiling up and down at each other in our mutual youthful shininess.

At one particularly unforgiving curve, I noticed you. A woman next to me cheerfully apologized to the men behind her, into whom she had just crashed. The men laughed it off with homosexual references towards each other, making it clear that neither were actually gay.

Since you and I were in such close quarters ourselves, I began jokingly to apologize as well, when I noticed something unusual. Perhaps you had a briefcase, or an umbrella, that was poking into my backside, but a glanced behind revealed that it was not so.

No other part of you was touching me. And I realized that we had been standing like this for a few minutes. Well, I was standing, but you were swaying a bit. My immediate reaction was to giggle, immaturely, like a high school girl after a particularly amorous slow dance.

Oh my God, I rehearsed to myself the story I would tell my friends later on. The funniest thing happened to me today on the train...

Then it was all I could think about. I moved forward slightly, a test to see if it was merely in my imagination, but you followed. When the train curved, we did not come into further contact, but when it straightened out again, there you were, behind me. Still swaying, slightly, against me.

You were not dirty, or disheveled, or old. You were maybe in your late twenties in an obviously expensive, greenish-gray suit with light gray silky sleeves poking out from the cuffs. I examined your hand, gripping the pole above my own hand. Okay hands, not particularly ugly or attractive, thick, with pronounced round fingernails.

You continued to rub against me, from behind, and I have to admit that for a little bit, I grew somewhat excited. This was the kind of scenario I would read about in a magazine, or see in a movie. The anonymity was slightly thrilling--did you even see my face? I briefly caught yours. Not head-turning, but pleasant, and if you were to come to me in a bar and strike up a conversation, I would probably have happily flirted with you. I caught glimpses of sweaters, hair, shoes and bags through the imbroglio, slightly smug in our tiny erotic secret. I began to speculate: would I turn around and kiss you? Would I wordlessly disembark with you, have speechless sex and disengage again as strangers? Would we get married and, smiling, never reveal how we really met?

I didn't encourage you, but I didn't discourage you.

Listen to this, I thought I would say later. I know this is strange, but the sexiest thing happened to me on the train today.

Passengers began disembarking, but the train remained crowded. As when people must reshuffle on crowded trains, I had to move to the other side of car. Our little scene was over.

But then you were there. You had said goodbye to your short, brown-eyed, similarly-suited friend and followed me. The train was no longer as crowded, but it was if as long as I was there, so would you, or at least your pelvis would be.

If I had thought that I was deluding myself earlier, I certainly wasn't by now. There you were, hoping that I would turn around, perhaps, but I coldly offered you only my hip and my elbow. I was at one point secretly pleased, but now slowly grew disgusted, then fearful. Your friend had left; would you be following me?

Oh my God, I would say later, the freakiest thing happened to me on the train today, I thought I would say.

At the closest chance, I grabbed a seat and pulled open my book, wondering if you would still follow, or perhaps stand in front of me so I could see that insistent part of you, eye to eye. I became disgusted with myself, as well as with you...why did I let you do that?

I became engrossed with my book as we passed more stops, the cloud of solicitousness passing from me as more and more people left the train. The heat in my face gradually cooled. Now and then, curiously, I glanced up to see if you were still there, but the other passengers stood in my line of sight.

Finally, at my suburban stop, I departed. You were gone. I felt strangely disappointed. The adventure, the excitement, the fear, the story had left with you.

As I walked away from the station, towards home, I realized that there was no story, no adventure, and nothing to be excited about. A pervert who decided to rub his penis on my ass, no matter how young or well-dressed he is, is still a pervert. I don't know why you did it and I don't know why I let you. Sexual encounters between strangers on a train are not sexy, I decided.

So I decided not to tell anyone.