Hit your best friend up, because casual straight girl on straight girl sex is the new black.

We're not proud of it, but we were lurking the Craigslist personals recently … Er, for a friend.

And during our internet spelunking, we noticed a very interesting trend. In the 'Women Seeking Women' section (um … R&D?), a significant portion of the ads weren't seeking relationships or casual hookups … they were seeking friends-with-benefits situations.

One post, from a 23 year old woman in Los Angeles, said this:

I am very straight girl, I love men all the way. But sometimes a girl has needs and because I don't sleep around I would love to gain a good friend around my area to go out have fun outdoors talk about boys and then sometimes if we have needs we can have fun with eachother!

Another, from a Denver lady:

I'm married, but looking for someone i can relate to talk to I've been living in Denver for 3 years in December and I underestimated how hard it is to make friends as an adult …  I'm looking for a friend that I can go get our nails done but also have mess around for fun and curiosity.

A third, from Thorton, posted this on the page:

Well, you can't really argue with that.

More and more these days, girls who identify as straight, and even mention their boyfriends or husbands in personal ads, are looking for casual lesbian sex. It's a somewhat recent phenomenon  the internet has dubbed "girlfriends with benefits," which we'll lovingly abbreviate as GWB to accommodate your severe ADD.

For many women, a GWB situation is about more than experimenting, feminism or simply giving up on dick. These hetero flexible babes know exactly what they want: long-term romantic relationships with men, but casual sex with women. That either manifests itself as a GWB scenario or some side-ass they get outside the confines of their straight relationship.

"It's a huge phenomenon," said Chelsea Reynolds to Cosmopolitan. She researches gender and sexuality in mass media as a doctoral student at the University of Minnesota School of Journalism and Communication.

In a study she conducted, she professionally lurked the 'Women Seeking Women' realm of Craigslist in 10 U.S. cities, including San Francisco; Chicago; Boston; Louisville, Kentucky; and Lubbock, Texas. After analyzing hundreds upon hundreds of personal ads, she estimated that, over the course of a year, there are hundreds of thousands of sex-soliciting ads posted online from ladies who "self-identify as straight, who want relationships with guys, but also enjoy a woman's body and affection here and there."

Reynolds said that when straight girls look online for casual gay sex, they retain their "stereotypically heterosexual" identities. That is, they tend to reference the men in their lives to make it clear they're not looking for a lesbian relationship.  Often, they'll self-identify as straight right off the bat because it helps them find the sort of GWB situation they're looking for. They're also prone to tossing out offers for girly BFF activities like brunch, shopping and mani-pedis, none of which are particularly relationship-y type activities.

Girls, it seems, just want a best friend they can fuck.  This makes cubic boatloads of sense, because usually, casual sexual relationships don't work with men. Emotions tend to permeate the boundaries of the friends-with-benefits negotiation, and one party eventually starts to feel more than they were supposed to.

Furthermore, female sexuality is so poorly understood by the majority of men, that many women feel the only way they can express themselves sexually is to be with someone who understands their body and thought process. Call it gay if you want, but it's not as much about labels and sexuality categories as it as about casual sex that can be pleasurable without the wet blanket of emotion. GWB situations offer freedom from that, as well as a space where sex can be experienced as sex and nothing more. 

According to Indiana University's 2014 National Survey of Sexual Health and Behavior, about 7 percent of women in the U.S. identify as gay, lesbian, or bisexual. However, the amount of women who have had same-sex hookups is much higher — closer to 12 percent, according to the same data. The numbers are higher yet among women 25 to 29; nineteen percent of ladies in that age group have had oral sex with another woman.

The idea that sexuality is a spectrum, not a category, and that a person can fall somewhere between kinda-sorta straight-ish or a teeny bit gay goes way back to the days of Alfred Kinsey, the famous sex researcher. He argued that while some people have definite sexuality categories (gay, straight, bi), many others experience a range of sexual interests that fall somewhere in between them. Sexuality, according to Kinsey, is fluid. Yet still, that decades-old idea has yet to catch on in mainstream America, who loves nothing more than to point a finger and ask, in a comically Southern accent, "What are you?" The answer, for an increasing number of women, seems to be both "everything" and "nothing" at once.

Of course, that idea is media gold. People love to watch chicks hook up more than they love their own children. Orange Is the New Black and its "gay for the stay" lesbian love affairs are hyper-addictive Netflix crack. Feverish gossip about Taylor Swift and her makeout buddy Karlie Kloss abound. On Glee, Santana and Britney are best friends and then oops, they're lesbian lovers who date boys too. And a recent survey by Cosmopolitan.com of 4,000 women found that almost 84 percent of straight female readers have watched lesbian porn. This isn't something to objectify, but that doesn't stop people from doing it.

As such, the number of women who describe themselves as pretty straight, but all the way hetero, is on the rise, says the most recent National Health Statistics Report. In 2008, 12 percent of women in the U.S. said they were "mostly" straight but have some attraction to other women, an increase from 10 percent in 2002.

Looking towards the future, it's possible that the expanding view of sexuality as a spectrum may lead to the death sexual labels altogether. We mean, look back to the early '90s; the concept of being unlabeled didn't even exist. So, the fact that we're at a point where women feel comfortable expressing their sexualities on a spectrum counts as progress. Men, however, not so much. But that's a whole other article, and we have to get back to Craigslisting "for work," so we'll leave that one be for now.

What's mostly important to know here is this is really why girls go to the bathroom together.