The final taboo: The one thing Hollywood still deems 'too much' to show on screen.

Anastasia Steele and Christian Grey are into all sorts of wacky sex. But there’s one type they wouldn’t try. Period.

Whether you love or hate the 50 Shades of Grey enterprise, one scene — or rather its absence — had everyone talking following the film’s release.

No, it’s  Christian Grey’s cringeworthy “I’m 50 shades of f**ked-up” line and it’s not the controversial belt-thrashing scene.

I’m talking about the so-called “tampon scene“, narrated by Anastasia in the book like this:

“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.”

Yep, they have period sex in the EL James book.

Hot, messy, raunchy period sex, up against the bathroom sink.

In the movie, however, Ana seems completely devoid of a period — even though the hot love affair takes place over the course of a full month.

It appears that, while the film is happy to refer to butt plugs, whipping and spanking and fisting — and while it notably incorporated contraception into its sex scenes — Ana and Christian are conveniently relieved of having to deal with the biological fact of menstruation.

Related content: THAT scene from 50 Shades of Grey won’t be appearing in the movie.

Now, period sex may not be everyone’s idea of sexy, but it’s reality for a whole lot of women — including Chelsea Summers, who sings its praises in an article for the Guardian, writing: “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.”

Summers’ not alone: one survey revealed that more than 40 per cent of women have sex on their period, while Cosmopolitan US claims that 62 percent of men would be “willing” to have period sex. Period sex has even been shown to relieve menstrual cramps, a factor no doubt driving at least a few couples to get down and dirty during that time of the month.

Related content: These men are turned on by period sex.

Given that so many people are doing it, why didn’t the infamous tampon scene feature in the film? Why, as director Sam Taylor-Johnson has revealed, wasn’t its inclusion in the film even “discussed”, as Variety reports?

And why, in a broader sense, does Hollywood shy away from discussing period sex as even an option for otherwise sexually liberated lovers?

It’s fair to say that menstruation isn’t exactly an everyday topic for mainstream films to tackle: Occasionally, you’ll stumble across a “first period” scene in a movie – My Girl or the Blue Lagoon went there, for example — but after that first cutesy, euphamistic coming-of-age moment (“daddy! I think I’m haemmoraghing!”), menstruation almost entirely vanishes from the big screen.

That’s the case in particular in relation to sex; Indeed, we can only think of a single Sex and the City scene involving Samantha Jones that tackled period sex at all.

Perhaps this is because, as Jezebel points out, menstruation is still regarded “as either taboo or a horror-show”, and it’s usually associated with old stereotypes surrounding menstruation as unclean, or as some sort of “curse”.

Those stereotypes are reinforced by EL James’ statement to Vanity that the film is “first and foremost a romantic love story”: as Summers writes, “Hollywood decrees that you have your love over here, and your blood over there, and never the twain shall mix.”

But surely it’s time to overcome old sexual taboos; God knows Hollywood has started to embrace a whole bunch of sexual acts that would’ve had a film banned, once upon a time,

Anal sex has been rather normalised (admittedly, that may be partially down to porn…); “Motorbutting” featured in this season’s Girls; and gay and lesbian sex — its presence once unthinkable on the big screen– is thankfully now explored in films and shows like Shortbus and Orange is the New Black.

But menstrual blood, it seems, it Hollywood’s last sexual taboo.

That needs to change.

Because, even if it’s not everybody’s cup of tea, period sex is a reality for many — and as Jezebel points out, it’s actually kinda cool and feminist and amazing in that “it represents a level of comfort and familiarity with the actual female body, not the sanitized version pushed by “lad mags.”

Summers agrees that the “transgressive” nature of the tampon sex scene in the 50 Shades book is exactly what makes it so awesome.

“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, “she writes.

“This is what is so very riveting, so very sexy, and so very transgressive.”

Related content: Rosie Waterland’s 50 Shades of Grey review.

There’s some more good news for those who embrace period sex: it opens up your opportunity for more sex, more often.

As Jezebel writes:” I’d argue that learning to like period sex is worth some initial discomfort, both because it adds three to seven days per month when you can bone.”

So, where do you stand on period sex? Do you think the tampon scene should have been included in 50 Shades?