If porn and dirty jokes are to be believed, straight anal sex exists for one reason: to make a man feel good. It’s a “birthday treat”, or a “reward for saving the planet” – but nobody ever seems to ask the women how they feel about the whole thing.

Well, that’s all changed now. A new study, published this week in the journal PLOS ONE, is the first ever to do exactly that: it’s a large-scale study, over a probability sample of more than 3,000 US women aged between 18 and 93 (which, by the way, fantastic work grandma, we should all be so lucky), about the specific ways in which anal touch can be pleasurable for them. The result, according to the authors is “an important expansion of the existing anus-focused literature in several ways.”

So what did the study reveal? Well, before we begin, we have to rethink what we mean by “anal sex”. After all, that term brings a very, well, immediate and specific image to mind, doesn’t it? As the researchers themselves put it, “existing studies most commonly operationalize ‘anal sex’ for women in terms of penetration of their anus with a male partner’s penis.”

But the Lesbian Avengers didn’t march on Washington just for sex to be confined to penetration with a penis. According to the study, there are a whole lot of anal sex tricks we’ve been missing out on: “through inductive, qualitative research,” the authors write, “we identified and named three previously undefined anal touch techniques that are found pleasurable by large proportions of U.S. women: Anal Shallowing, Anal Surfacing, and Anal Pairing.”

And don’t worry, we aren’t about to leave you hanging: the researchers provided detailed descriptions (with diagrams!) of the techniques, and so will we. “Anal shallowing” refers to “penetrative touch ... just inside the anal opening, no deeper than a fingertip/knuckle,” they explain – a technique that 35 percent, or more than one in three, of respondents reported enjoying. 

Then there’s “anal surfacing”: “sexual touch ... on and around [not in] the anus,” which was even more popular – 40 percent of women reported finding it pleasurable. Finally, “anal pairing” – not an X-rated file-sharing technology, but “touch on or inside the anus ... at the same time as ... vaginal penetration or clitoral touching,” also scored a healthy 40 percent approval rating.

But why, you might be asking, should we care? Who’s funding science about butt sex? Is this what I pay my taxes for?! And we admit, this could be seen as a somewhat frivolous study – but actually, it has the power to affect our lives much more directly than less-taboo research.

“When there aren’t even words for things, they’re literally made ‘unspeakable’,” the researchers write. “The language of sex is historically clinical or slang – not descriptive about what women enjoy and not in service to women.”

We have terms like rim job or fisting, the study points out – or, if you prefer, anilingus and brachioproctic eroticism – but until now, no name for some of the most common pleasurable anal experiences for women. And even if there were such terms, we might not know about them, since the authors note that almost all anal sex information is concerned with the potential risks or stigma associated with penile penetration, and the various ways women might dislike or be coerced into it.

“Next to nothing is known about either the ways in which women actively choose different techniques that are not penile-anal penetration or about how pleasure levels may vary across these techniques,” the study notes. “Popular print and electronic media interest in anal sex has increased in the past decade … [but] these sources rarely acknowledge a wider repertoire of anal stimulation and stimulation methods that women can and do choose.”

“Our detailed, nationally representative data on the prevalence of women’s participation in techniques and their variants, their technique discovery, and their motivation for techniques, is an important validation for women,” the study concludes. 

“Individuals like themselves can and do actively choose anal touch and stimulation to meet their own personal pleasure needs. Information such as this is vital for women’s ability to ‘normalize’ their participation in and motivations for a behavior that is often socially stigmatized.”