I am a big fan of period sex.

Part of my enjoyment is that I came of age in a place (Vermont, renowned for its woodsmen and its hippies) and a time (the late 70s and early 80s) that were conducive to being matter-of-fact about female bodies. The very first time I had sex during my period was on the floor of a nearly-empty college apartment with a guy I was dating; I had no idea that I had gotten my period while we were shagging. I went to the bathroom and, in the greenish cast of the fluorescent lights, I saw the blood. I thought it was pretty cool.

I walked out and told the guy. “Oh,” he said, looked down at his crotch, and offered me a beer. It was no big deal to him.

Period sex has rarely has been a big deal to the men I sleep with – and, if it is, we go our separate ways. I couldn’t love a man who doesn’t approach my menstruation with the same pragmatism I do. Sex feels good, menstruation is a fact of my life, and, as far as I’m concerned, period sex is what dark towels were made for.

Many women – and men – didn’t have the benefit of growing up in a place and during a time in which either women’s bodies or our bodies’ natural processes were viewed without horror. These people often need reassurance that their bodies in their natural states are as sexy to others as they feel to themselves.

Reassurance is why the scene in Fifty Shades of Grey that begins, “‘When did you start your period, Anastasia?’” is one of the most beloved, most celebrated erotic moments in EL James’ book. It inflamed imaginations when the book came out, but Hollywood chose not to film the scene; the director, Sam Taylor-Thompson, said, “It was never even discussed”.

But do a quick Google search for “50 Shades tampon scene”, and you’ll get almost 20,000 results – a number that suggests that even if the film’s makers didn’t want to discuss it, lots of other people do.

Hollywood doesn’t like to mix its blood and its love – it likes to reserve blood for horror and, while horror movies will show sex, they inevitably end with someone bloody and dead (usually the woman). James’ response to the scene’s omission – that “first and foremost a romantic love story” – further elucidates the supposed incompatibility between love and blood: Hollywood decrees that you have your love over here, and your blood over there, and never the twain shall mix.

That, as most happy, loving couples of at least one female-bodied human can tell you, is pure fiction. Many women love menstrual sex – and, even if they don’t, the controversy over its omission in the movie testifies to its power on women’s imagination. The question isn’t whether women often eroticize their periods; the question is why?

The key might be in the utter banality of the visual of got cut. “He reaches between my legs and pulls on the blue string … what! And … gently pulls my tampon out and tosses it into the nearby toilet”, Anastasia narrates in the novel. The erotic frisson of Christian Grey removing Anastasia’s tampon derives not merely from the fact that, faced with her menstruation, Christian proceeds with his erotic education of young Anastasia; it’s that he removes her tampon himself and then boinks her against the vanity.

The prosaicism of the gesture is the symbolic lynchpin of the whole erotic enterprise; it both the thing that grosses out some readers, and the thing that enchants many more. In removing Anastasia’s tampon himself, Christian embodies a desire for women that transcends the disgust that culture has made men and women feel about female bodies. This is what is so very riveting, so very sexy, and so very transgressive.

Any erotic depiction that erases the shame that women feel about their periods is a good thing. Periods are not a “curse”. Menstruation is not “woman trouble” – or even “being touched by the goddess”. Periods are a routine fact of most women’s lives; and period sex is a joy, not a horror. It not only should be discussed, it ought to be depicted.