I know what you're thinking: Surreptitiously rubbing one's crotch against nonconsenting women in crowded areas in order to achieve sexual arousal sounds like a walk in the park. But whenever I hear someone talking about how "simple" it must be to be a frotteur, I just have to laugh.

Believe it or not, inconspicuous genital friction is not all fun and games.

Contrary to popular belief, frottage takes hard work and dedication. Unlike building a deck or performing surgery, there are no instruction manuals on how to properly press your penis up against someone's hip on a packed train. These are things I had to teach myself. It takes a surprising amount of practice and a fair share of embarrassing failures in front of large groups of people to really get it right.

Most people assume that frottage is as simple as dropping by any cramped or confined space, strolling up to the first unsuspecting female you see, and doing your thing. No way, José. If it were that easy, everyone would be a frotteur.

In reality, you have to consider an almost endless number of variables before you can even think about enjoying the act of secretly stimulating yourself against a bystander's body: leverage, weight distribution, thickness of fabric, momentum—the list goes on. Paying attention to whether your target is carrying any foreign objects in her pockets is also paramount. Grinding your phallus against someone's keys is no fun at all, and barely arousing.

But frottage is not just a science; it's also something of an art. There are certain intangibles that cannot simply be "learned"—like the ability to cup one's hand in a concave semicircle and tap the buttocks of the woman in front of you in such a rhythm that it simulates the unintentional contact of a swinging duffel bag. Not just anyone can pull off that level of furtive sexual pleasure. You've either got it or you don't.

No one thinks about the hours and hours of preparation frottage takes, either. Every single day, I'm up at the crack of dawn to catch the crowded rush-hour train. I bet you're saying, "Hey, a lot of people do that." Well, you try maintaining an erection at 8 a.m. without your morning coffee. Good luck. You also have to contend with factors such as the reshuffling of the crowd at each subway stop, hip-length messenger bags, women who don't tolerate someone vigorously gyrating against them, and a whole bunch of angular geometry that I don't even want to get into. Let's just say it sort of takes all the mystique out of groping.

Now don't get me wrong, there are definitely parts of frottage that are truly rewarding. Like the feeling of your penis hardening as you thrust it into a nonconsenting woman's backside, and the part where you ejaculate in your pants. But there are downsides to frottage, too.

Just the other day I was on the train with this beautiful creature in front of me. Everything's going smoothly: I'm leaning in at a nice 80-degree angle, got a good rhythm going, when all of a sudden, the woman starts screaming and hollering. Talk about a mood-killer. Of course, they end up stopping the whole train, so now everyone is mad at me, and I've got two policemen asking me all these personal questions. What a hassle!

Sometimes I wonder why I keep doing this.

It's getting to the point where it's almost impossible to engage in a little frottage without some big commotion. Gone is the golden age of frottage, when the trains would rumble and shake along bumpy tracks, each jostle and jolt sending one's genitals deeper and deeper into an unwitting passenger's side. And women who did realize what was happening would just stand there quietly against the wall while strange men used their stiff, motionless bodies as a means of sexual gratification. Those were the days! Sadly, modern train cars are more spacious, the rides are smoother, and people have changed. It's almost like the world is trying to make it harder for us frotteurs.

My one hope in life is that people will someday see that frotteurs have it no easier than anyone else. The next time you're in a crowded subway and you feel something small and firm bumping against your lower back, it just might be one of us. So show a little respect and let the guy keep going until either he has finished up or it's your stop.