“I can imagine two women together, but not two men,” my sweet but rather conservative sister told me during one of those run-of-the-mill family discussions about homosexuality. A guy said the same thing to me the other week. It got me thinking.

My sister’s justification for her statement was that she believes women’s bodies are just softer and nicer to look at, and that it just seems more natural for two women to be together. The guy told me it was because he loves women, so he can understand one woman loving another woman. “I don’t love men, so I can’t understand what it’s like to love a man,” he explained.

Hmmm... I suppose that’s why porn aimed at straight women is full of boy/boy scenarios. Except it isn’t. Most women would also rather see two women having sex in their porn than two men. (Including my sister — she’s not that conservative.)

Sure, there are exceptions. There are straight women who can’t stand the idea of two women together. And there are straight women who get completely turned on by gay male sex. “It’s more to the point,” as one female friend tells me. She finds all the long-winded plotlines of women’s erotica tiresome.

And there are straight men who aren’t turned on by the idea of two women together. No really, there are — I’ve met him.

But generally, two women having sex is a much more common and acceptable fantasy for straight men and women alike. Part of it has to do with the fact that we’re more used to seeing women depicted sexually in our culture.

There are other reasons that straight porn doesn’t tend to feature many boy/boy spreads, beyond the fact that women look better airbrushed. “The whole lesbian-fantasy thing is less threatening,” one woman at the Messy Bedroom Research Centre (a.k.a. the local bar) offers. “There’s no penis.”

And usually no lesbians. If they were really depicting lesbian sex, the women wouldn’t feel the need to master the art of licking pussy and looking at the camera at the same time. They’d be focusing on the business at hand. “For men watching, I think there’s the idea that the women are performing for them,” one guy suggested.

Which doesn’t explain why most women prefer it. If we buy earlier “I-only-understand-loving-women” guy’s logic when it comes to same-sex fantasies, women should be turned on by gay-male sex, right? But aside from my aforementioned gay-smut-snaffling friend, most women aren’t. “I’ve shown women some of my gay porn,” a gay male friend tells me. “They find it interesting but not a turn-on.”

There are studies that claim that women are more bisexual by nature, that their sexuality is more fluid so it’s easier for them to imagine themselves with another woman. Perhaps, but I also suspect it has a lot to do with the fact that, culturally speaking, men are given a harder time for colouring outside their traditional gender-role lines than women are. A straight woman, for instance, can casually mention she’s thought about sleeping with another woman, but a straight man will be less comfortable mentioning that he’s thought about sleeping with another man.

And team sports aside, we’re more accepting of women being more physical in general. You’re not going to see two straight guys walking down the street arm-in-arm in this country. And two guys are more apt to shake hands than hug when they greet one another. Most straight women are more at ease being naked in front of each other too. I know two guys who lived together for years and claimed never to have seen each other’s penis.

“I think [straight men’s discomfort with male-male sex] is all based on the fear of two sets of hairy balls rubbing together,” was one, I thought, particularly astute take on the whole thing. I’ve certainly heard stories of male porn actors refusing to do threesome scenes involving two men and one woman because they “weren’t gonna touch no guy’s genitals.”

This is all based on stereotypes, of course — stereotypes that I like to think are slowly breaking down. Hopefully, one day, straight men won’t have to play football in order to be comfortable getting physical with each other.