If you're squeamishly wondering how much the college senior gets paid for submitting to these weird acts of perverse, pornographic violence, brace yourself for the truly agonizing part: It's actually Pinto who shells out the cash, paying her regular waxer, Anna, more than $65 every time. But it beats the ingrown hairs and razor bumps that come from shaving, she says.

Sound excruciating? Sure is, says Pinto, who pops two Advil before each appointment. But grooming habits like hers hardly raise an eyebrow among the under-30 set. Today, it's all but commonplace for women to go to extreme measures to get bald, pre-pubescent nether regions: Indiana University researchers Debby Herbenick and Vanessa Schick found in a recent study that nearly 60 percent of American women between 18 and 24 are sometimes or always completely bare down there, while almost half of women in the U.S. between 25 and 29 reported similar habits. Herbenick's numbers show a clear-cut trend: More women lack pubic hair than ever before.

What's happening to America's vaginas? Is pubic hair going extinct?

In a word, no. But it's on the fast track to the endangered species list, and its chief predators include the porn industry, smaller bathing suits and lingerie bottoms, and the Kardashian sisters (case in point: Kim once famously proclaimed that women "shouldn't have hair anywhere but their heads").

Pubic hair is, however, evolving. Once upon a time, all vulvas were coated in a protective layer of coarse, woolly tresses. Hard to believe, right? It's kind of like the revelation that horses once had toes, or that the Ford Mustang once had tailfins. But like any evolving species, the vulva has morphed into something sleeker, starker, and altogether more modern. Today, it is smooth, baby-soft, and hairless.

A BRIEF HISTORY OF THE HAIR DOWN THERE

The most staggering aspect of the bald-vulva phenomenon is just how quickly women (and men) have embraced it.

Less than two decades ago, the idea of "taking it all off" seemed painful, unnecessary, and even vaguely fetishistic; As recently as 1996, one harrowing, particularly memorable vignette from Eve Ensler's groundbreaking play The Vagina Monologues effectively turned the idea of removing pubic hair at the request of a sexual partner into something cringe-worthy and perverted. Trimming away a few strays during swimsuit season was one thing, but removing all the hair from one's genitals, effectively turning back the clock on puberty? Traumatizing. Selfish. Inhumane, even.

Or not. Enter the seven Padilha sisters, immigrants from Brazil. In 1987, Jocely, Jonice, Janea, Joyce, Jussara, Juracy, and Judseia Padilha opened the appropriately named J. Sisters salon in Midtown Manhattan, where they began offering what they had dubbed the "Brazilian wax." Years before, a woman in a thong swimsuit with an ungroomed bikini line had strolled by Janea Padilha as she lay on the beach. Why not just wax the full bikini line, she wondered. The peculiar practice would go on to change the world of female genitalia as we know it -- but not for another decade or so. Instead, it would remain weird, taboo, and rarely administered for another 13 years.