Written by DCist fashion contributor Rachel Cothran. Find more of her writing at her web site Project Beltway.

Mauro Farinelli’s favorite word is ass.

“Your ass looks hot,” he tells me, pronouncing it the same way you’d say “ouch” after stepping on something sharp. “You have a great ass,” he determines matter-of-factly.

And what Farinelli says, goes. The thirtysomething owner of local jeans mecca Denim Bar has a magnetic personality and the certain know-it-all attitude that makes you instantly trust his judgment and covet his approval. If you let Farinelli work his magic, if you’re open to it, you won’t be sorry. But Denim Bar is not for the faint of shop. You have to not only want to find the perfect pair of jeans, you have to be open to the experience of denim. You have to be interested in terms like “whiskering” and “yoke” and “busted seams” and care about things like raw denim and real indigo dye (he’s selling a pair made with 100 percent natural indigo for $750, if you’re interested). Farinelli is the Denim Moses who will lead you out of style slavery and into the sartorial promised land.

But you’d need to know that salvation often doesn’t come cheap. And you’d need to have the courage to admit that those Gap jeans ain’t cuttin’ it.

At Denim Bar, the “good stuff” is behind the bar: the most expensive jeans and the booze you just might be offered while you shop (bloody marys on Sundays). Entering the flagship Arlington shop is a bit intimidating. There’s little more than stacks upon stacks of denim nestled into dark-wood walls; you can hardly be the shy “just looking customer.”

I arrived at the store with my friend Matt, who quickly impressed Farinelli with his fashion knowledge and by wearing ridiculously hot and expensive Prada jeans. I told Farinelli about my favorite jeans, a pair made a few years ago by Paper Denim & Cloth, now as frail as phyllo dough. I needed to find the next best thing. And I wanted Farinelli to do all of the work. He knew Matt’s and my size with a quick glance, and soon enough we were in our respective dressing rooms with three pairs of jeans.