It's not always easy to have a frank conversation about anal sex. Stereotypes are rife, opinions are strong and taboos make it hard to talk about.
Given how immensely popular it is in porn, this reticence in real life might seem a little peculiar. More and more heterosexual couples are doing it, research has shown, but honest conversations about how women in particular actually feel about anal are lagging well behind.
For women, this is partly because of the sense of shame around the topic. While a man might feel open or even proud of himself for doing anal, women feel they will easily be judged and stigmatised if people know she's done it, according to a study recently published in the Journal of Sex Research.
"Within heterosexuals, this idea of anal intercourse and more broadly anal sex behaviour have really been understudied," study author Kimberly McBride of the University of Toledo told IBTimes UK.
"We have really good documentation about incidence, prevalence rates, and health outcomes – so things like HIV and STIs – but until now we really haven't done a good job of understanding some of the factors that influence women's behaviours in particular."
McBride's research centred on several focus groups involving a total of 33 young heterosexual women in the US, who have been anonymised. While the women differed on many points, they broadly agreed that anal sex was emerging as a new norm for straight couples. Despite this, there is a strong sense of fear of social judgment if people found out about it.
"I feel like it's something that a lot of people try, but no one really talks about," said one 27-year-old woman. "A lot of people talk openly about vaginal sex, but it's a taboo thing to talk about [anal sex]."
This stigma puts a limit on how much women can enjoy anal sex, the group believed. Men, on the other hand, don't have to worry about that.
"If a guy speaks about anal sex, everyone is like, 'Oh man, it's so great.' Whereas if a girl says, 'Oh I've had anal sex' and is proud about it, she gets labelled a slut," as one 24-year-old put it.
Given this, it's no surprise that the most common reason the women said they or female friend had had anal sex was because their partner wanted to, rather than it being her idea.
"A lot of people aim to please because most general guys like to do it," said a 28-year-old participant.
"For me, it wasn't because I wanted to... it was because he asked," added a 24-year-old. "And from there it is just something you do... I wasn't trying to please my own self."
Some women had a positive take on this, suggesting it was a rare treat for the male partner that they didn't mind giving. Trust that the partner wouldn't reveal that they've done it was crucial to this, as "bragging" could expose the women to judgment and feelings of shame.
But for other women, anxiety was a big part of their reason to agree to anal sex. Women in the group related to the pressure of not disappointing their partner and even fears of losing him if she said no.
As one 27-year-old said: "They goin' do what they feel they need to do to keep that man. If he wants the booty, that's what they are going to give him."
Beyond the negativities of stigma and relationship anxieties, women in the group also expressed curiosity and pleasure from pushing the boundaries of what is considered acceptable. One 20-year-old participant described a friend who ended up preferring anal sex to vaginal sex.
"When she first started having anal sex she liked it better than regular vaginal sex because it was, like, different and new and taboo... she still likes the novelty of it," she said.
Much of the physical pleasure women described around anal wasn't from full penetration with a penis, but from rimming, or oral stimulation of the anus. The same participant said another friend enjoyed receiving this because "she felt like a goddess, like she was being was being worshipped". The fact that her partner was willing to violate a social taboo for her felt like a sign of true devotion.
"If he's gonna lick my butthole, he totally loves me."
Other women reported experiencing similar feelings of pleasure with fingers or manual stimulation of the anus as a way to enhance vaginal sex.
"So we will have sex doggy style or something, and he will use a finger or some type of vibrator, and that is actually very pleasurable," said a 26-year-old. "Just kind of barely having something there, having that vibration there, for me, personally, it is a nice sensation in addition to us having sex."
As soon as a penis was involved, things got more complicated. All of the women who had tried anal sex said that they had experienced some level of pain.
"That shit is terrible," said one 26-year-old. "I've tried it. I've tried a lot of stuff, but that is just – no."
Whereas others said that they became accustomed to the pain over time.
"I don't think I'm going to die. I think it's pretty fine. I think it's painful, but you get used to it after a while," said another 26-year-old.
The women discussed fingers and sex toys as a way to prepare for anal sex, make sure they were comfortable with it and reduce the likelihood of pain. They described toys as a way to "ease into it". Preparing properly, for example by using lubricant, rather than doing it on the spur of the moment was essential, the group said.
"I feel like sometimes there are steps for people. They will try the less intimidating things, which would be like fingering and toys, to see how that goes. Then the next step would be the penis," said a 23-year-old.
An open mind
McBride's study is only just starting to reveal some of women's attitudes and motivations to have anal sex. The points the women raised in this research seem to tie in well with previous findings.
"There are clearly a variety of reasons women engaged in anal intercourse, but the desire to please a partner or solidify a relationship comes up a lot," McBride said.
"There's a feeling of doing it to compete with other potential partners. You know – thinking, 'Wow this woman won't do that but I will so maybe he'll choose me.'"
But aside from anxieties and wanting to please others, women were clearly trying to find ways to explore anal sex, and anal play such as receiving rimming, on their own terms.
"Women did talk a lot about pleasure and were trying to navigate ways to experience anal intercourse as something that was pleasurable," McBride said.
"They're looking for strategies and technologies to help them. They're asking, should I be using lubricant, if so what kind? Are there other things I can do to make it enjoyable?"
And even if many of the women in this study had experienced pain from anal sex, or they hadn't found a way to experience pleasure from it yet, some were open to the possibility of it in the future, and didn't want to discount that other women might find it pleasurable.
"The take home message isn't that this is a violent or coercive thing. This is part of relationships. It's very complex and women are trying to figure out ways for it to be an exciting, pleasurable experience."
Navigating this course is certainly a tricky thing to do in a society that shames women who take part in or enjoy anal sex.
"This is an area where there are so many stereotypes, and everyone has strong attitudes," said Cynthia Graham, professor of sexual and reproductive health at the University of Southampton and editor of the Journal of Sex Research.
But despite the stigma, according to national surveys, anal sex is becoming increasingly common among heterosexuals, suggesting there is an awful lot left to learn about why women – and men – do it.
"I think this study shows just how much variability there is among women and in what women enjoy in terms of sexual activities.
"Studies have shown that people's repertoire of sexual behaviours is broadening out, and this is particularly true for women. There's definitely still a gap in terms of our knowledge about anal sex and why women do it. We're only just starting to answer that."