I originally got this off of here:
http://www.tadpolenet.com/blogs/index.php?blog=5&title=do_not_shave_your_ass_hair

But I think it might be from here:
http://www.craigslist.org/about/best/lax/35274458.html

Don’t Shave That Hair!!!
I have recently made a mistake in my life, and I offer my story to you, that you may learn from my error. It all started, as many things do, with me having trouble shitting.

No, I was not constipated; this was not a regularity problem but a matter of technique. It seems my ass-hair had grown to such a length that tiny grogans were constantly getting tied up in the matted jungle between my asscheeks. It led to much frustration, with me KNOWING that I still had something to drop, but unable to shake the tenacious turd loose from its butthair dwelling. Eventually I would have to do two things: either reach down with some paper and try to pinch off the lingering loaf (which required careful precision to avoid smearing the creature all over my rear, especially since I had no way of seeing what I was doing) or just go for broke, start wiping, and hope that I could remove all the leftover fecal matter before the toilet paper reached its Can’t-Be-Flushed threshold.

I was contemplating this problem, when I had what seemed at the time to be a bright idea. “Hey! This is my butt and my butt-hair, right? So why don’t I just eliminate all the hair, and then my grogans will flow out like beer from a keg!” I said to myself. It is a statement that will go down in history with a lot of other regretted statements. “How many Indians could there be?” said by General Custer. “Looks like a good day for a drive!” by JFK. “There! America On-Line now has complete Usenet access!” by some idiot system tech. Such was my anal shaving idea.

I performed the operation that night, with a cheap disposable razor and a towel to sit on. Starting from the bottom, and shaving from the crack to the cheeks, I began the arduous process of ridding my ass of hair. Occassionally, I would have to clean the razor of accumulated hair and miscellaneous slime, which I did by wiping it on the towel. Slowly, my twin mounds and the between-ravine began to resemble the hairless cheeks of a newborn baby. Finally, I wiped the razor one last time, and surveyed my work. The towel was covered with a pile of hair. My ass was smooth as ivory. I smiled, satisfied, thinking my troubles were over.

Little did I know.

I now have a great respect for anal-hair. Like everything in this world God created, it has its mighty purpose in existence. It was only after I had removed it that I started to learn how much I had been taking it for granted. For one, it provides friction. I learned this the next day, when I walked out into the sun heading for class. After climbing two flights of stairs and starting to sweat, I started to notice something unpleasant. The sweat was accumulating in my crack, and was causing the unpleasant sensation of my two asscheeks sliding past each other with every step. I thought about going to the bathroom and wiping it off, but had to get to class. Eventually, I thought, it would dry.

Unfortunately, it did dry, but only after mingling with the microscopic shit- molecules lingering around my brown starfish. When I stood up after class, my cheeks were stuck together with a slimy sticky shit/sweat combination. As I made my way back to my dorm, it started to itch. God-DAMN, did it itch! Felt like a swarm of ants was making its way up and down my crack. Fighting to keep from jamming my hand down there and scratching away, I rushed back to the dorm.

Unfortunately again, this exertion caused me to sweat, and when I finally reached my room, my cheeks were sliding back and forth against each other like a pair of horny cane-toads. I quickly dropped my pants, and attempted to dry my ass off by sticking it in front of a fan and spreading my cheeks. As I pulled the two mounds of flesh apart, a horrible stench burst free and filled the room. Every dog within a 4 block radius started to howl. I had it worst of all, as the ripe aroma of festering shit/sweat went into the fan and blew back into my face. I fought to keep from heaving. And as I sat there, fighting vomit, my ass cheeks spread and dripping, with the concentrated aroma of my body odor mixed with the tangy smell of my own shit blowing right into my face, I had only one thought: “It will be like this until the hair grows back. Weeks.”

Later on, trying to deal as best I could, wiping my ass at every opportunity, I discovered another wonderful use for ass-hair – ventilation. I attempted to launch a fart, only to have it get stuck between my asscheeks. Apparently, with no hair, the two pink twins can get vacuum sealed together, and the result was a frustrating fart that slid up and down between my cheeks like a lost gerbil.

As if that wasn’t enough, I am now enduring further torture. As anyone who has ever shaved anything knows, when hair is first growing in, it comes in as stubble. Imagine your ass having the texture of a brillo pad. Well, that is what I am dealing with now. It is a hellish torture, and there are many times when I just look out the window and contemplate why I shouldn’t just jump out and get it all over with in one fleshy splat, rather than endure this constant agony.

Friends, DON’T SHAVE YOUR ASS-HAIR!