Over the years, Karen, 35, has established exactly what she likes when it comes to online porn. Three or four times a week, she goes in search of new videos in some of her favorite categories — Big breast play. Squirting. Lesbian. When she spoke to The Huffington Post, Karen had recently watched a video that hit all of her sweet spots: two women who didn’t have “perky, fake boobs,” but instead looked real, like they could be moms. They were in bed, kissing and fondling each other.

“It was nice,” said Karen. “Sensual.”

“I gravitate to what gets me going quicker,” she continued, “which is girl-on-girl.”

But Karen is straight.

There is little good data on how many self-identified straight women regularly watch woman-on-woman porn, but what evidence is available suggests Karen is hardly alone. A 2014 report from the free porn site Pornhub in collaboration with Buzzfeed, for example, revealed that “lesbian” was far and away the top viewed category among its female users, as well as the top search term — and women were 445 percent more likely than men to search for “girl on girl.” Though the survey relied on Google analytic demographic stats and therefore did not capture users’ sexual orientation, the overwhelming popularity of those terms hints at a lot of straight women getting off on same-sex porn. So does the marked uptick in searches for “lesbian seduces straight girl,” which increased by 328 percent between 2013 and 2014, according to PornHub’s internal data.

And sex experts agree.

“The statistic thrown around now is that 1 in 3 adult users of porn are female,” sex therapist Kimberly Resnick Anderson told The Huffington Post. “Though there is no way to say what percentage of that 1 in 3 are straight women looking for lesbian porn, the numbers are too high for it to be just gay women. Straight women are looking at lesbian porn.”

The industry appears to be taking notice. PornHub estimates that 7 percent of its videos are in the lesbian category, making it the site’s most popular category overall, Corey Price, the site’s vice president explained in an e-mail to The Huffington Post.

“While we don’t want to speculate on how this interest [from straight women] has changed and shaped the industry,” Price wrote, “we have noticed our content partners have been uploading more lesbian content than ever before.”

For many women, same-sex porn provides an opportunity to imagine what it might be like to be with another woman, even if they consider themselves on the strictly heterosexual end of the Kinsey scale. For them, lesbian pornography — which for purposes of this article simply refers to porn starring two or more women, not porn that is necessarily geared toward lesbian or bisexual women or even features actors who identify as queer themselves — is purely a fantasy, not a desire they want to act on.

“There’s this disinhibiting factor of the Internet,” Resnick Anderson explained. “People feel so free to explore things they would not necessarily want to do in real life, but that might be compelling to look at or learn from.”

Vickie, 46, says that’s the case for her. She has never been intimate with a woman in real life, nor has she ever given it much thought, though she considers lesbian porn her “get-off choice” and watches it three or four times a month, often with her husband. She has a clear physical type she seeks out — women with thin or medium bodies and long hair. “I like fingernails,” she said.

But Vickie has never encountered a woman in real life for whom she has felt any kind of sexual attraction.

“Lesbian porn is just much more fantasy-based,” she said.

For other women, the appeal of lesbian porn is a little bit more complicated, allowing them to express a part of their sexual identity that would otherwise remain locked. Karen, for example, has questioned her own sexuality at various points in her life, particularly in her early 20s. She now identifies as straight, but says she would be open to experimenting with women in real life — if she weren’t too timid. Same-sex porn helps her virtually scratch that itch.

“I’ve never experimented, but I think about it,” Karen said. “I think I’m so nervous and shy when it comes to that, I’d probably never follow-through.”

But Resnick Anderson said that much of the appeal of same-sex porn has little to do with potentially complex questions of sexual fantasy and fluidity, and more to do with the simple fact that much of the lesbian porn that’s out there tends to give more air time to acts that actually get women off.

In other words, oral sex.

“Seventy to 80 percent of women are unable to reliably achieve orgasm from intercourse alone, so oral stimulation is going to be more erotic to them,” Resnick Anderson said. “There also tends to be more foreplay. Whereas in the straight porn, it may go straight to the f**k scene or money shot. In lesbian porn there’s a focus on breast stimulation. It tends to be more tender and more intimate.”

“I like certain acts,” Vickie agreed. “Basically, eating out and also toys.” The heterosexual porn she’s watched tends to focus on penetration and leaves her with the sense that when they do go down on women, the men aren’t necessarily all that into it or particularly skilled.

“For me, it’s more that women know what women want,” she said. “How to do it and how to get it.” Ninety percent of the time, she imagines herself on the receiving end of oral sex she’s watching.

Hilary, 50, echoed the sentiment, and says she has even used lesbian porn as a kind of instructional tool for her fiance.

“I think guys tend to think, ‘If I just use my finger or penis, she’s going to get all this enjoyment and have an orgasm,’” she laughed. “I can show him, no, pumping in and out doesn’t work, and there are other parts of the body that are as much of a turn on as the vagina. It’s not that he’s inept at all, but I can watch it with him and say, ‘Oh, playing with my breasts like that might be nice.’”

If heterosexual porn provided more of what these women were looking for — foreplay, oral sex and women who seem to be actually orgasming rather than just shrieking theatrically — they might be more interested, they all said.

Instead, they’re content to get what they need from the woman-on-woman world.

“The main focus in straight porn is either the male partner’s pleasure, or [giving] the impression that he is a ‘master lover,’” Sarah, 23, wrote in an e-mail to The Huffington Post. “With women, the motions and movements during mutual masturbation, or oral sex, are far less fast and furious.”

Lesbian porn provides the best approximation of what she actually craves in her real life: A sense of genuine enjoyment. A skilled partner.

In other words, just good sex.

For privacy reasons, the women in this story used only their first names.