A movie about sex – kinky sex – is in cinemas, and as a film critic, and therefore a noted arbiter of good taste (bear with me), I’m expected to regard this adaptation of a smutty bestseller with derision or, at best, suspicion. But let’s take a different tack, shall we? Why not approach the film with a sense of generosity? After all, if box office predictions are to be believed, this will be the first big money-maker in a decade or so to feature explicit-ish sexy times (give or take a Wolf of Wall Street). This could represent a shift in big budget filmmaking, so let’s take it seriously.

I can understand why other critics may not be so forthcoming with their generosity. I’ve never read Fifty Shades of Grey; nor have I read – or watched – any of the Twilight saga that inadvertently birthed this piece of pitch-shifted fan fiction. But just as you get a pretty good sense of Twilight via osmosis working as a teacher in an all-girls’ high school, it’s nigh impossible to avoid Important Opinions about Fifty Shades. These opinions – or at least, the ones I’ve been exposed to – tend to oscillate between the two poles of “it’s terribly written” and “it romanticises an abusive relationship” (add “it’s not representative of S&M” to taste).

I’ve seen enough excerpts from E L James’ novel to take these opinions on good faith. But the book is too damn successful to totally dismiss – financial success may not indicate great, or even good, art but it sure suggests that the work in question hit a cultural nerve. It might be hard to extricate any nuance from Ms James’ fantasies, but cinema tends to provide perspective. Take Wolf of Wall Street again, which turned a pile of faux-self-deprecating braggadocio into a film both entertaining and incisive. There’s no reason to think that the director of the Fifty Shades adaptation, Sam Taylor-Johnson, and screenwriter Kelly Marcel can’t find similar flashes of insight amongst the smut.

For the first hour or so, they do a bang-up job. Taylor-Johnson cleverly slaloms between the tone of a goofy-awkward sitcom (much like star Dakota Johnson’s short-lived series Ben and Kate) and sleek, luxury-car-commercial ambience (precisely lensed by Seamus McGarvey). It sounds like a dicey combination and, okay, sometimes it is, but this choice single-handedly redeems much of James’s clunky dialogue. Take this godawful piece of prose:

On paper, it’s hard not to cringe. In a crowded cinema, everyone laughs. Is this intended by the filmmakers, or is it the laughter of a film taking one step too far into bad(movie)land? I don’t think it really matters; either way, you’re laughing, and surely that’s the exact reaction the novel drew from a good percentage of its readers.

Let’s not reduce the film to laughing at bad writing, though. There’s quite a bit to like in the first half of the film once you acclimatise to the dimestore dialogue. Jamie Dornan may not be the Matt Bomer fans demanded, but he’s sexy and confident and manages to sell the self-made-millionaire-with-a-tragic-upbringing bit with aplomb. He’s the kind of old fashioned prick who takes umbrage at having his sexuality questioned and confuses privilege with hard work, but he’s still abundantly charming. Dakota Johnson, meanwhile, turns the “nervous and mousy” knob up to eleven and gradually dials it down over the course of the film; that might sound simple, but she has to walk a careful line, character-arc-wise, and she nails it.

Much has been made of the two actors’ complete lack of chemistry off-screen, but let’s remember that they’re actors; their entire career revolves around faking this sort of thing. They sold me, anyway – a few smouldering stares and I was convinced that they wanted to jump each other’s bones. The big question for most fans, of course, is how’s said bone jumping? The sex scenes – particularly the first couple – are quite hot. Having a female director behind the camera helps a lot here, I think; the camera lingers without leering (also: bravo for not cutting around the condom. Safe sex can still be sexy!). There’s a sense of patience lacking from most on-screen depictions of horizontal mambo. However, despite all the fanfare about the book’s peek into S&M, it’s mostly vanilla; save for one scene towards the end of the film, the roughest we get is some soft tapping with a riding crop. I can’t be sure if this is simply a much more sanitized take on the novel, but it was very different to what I was expecting going in.

But the sex scenes only make up a fraction of the two hour runtime (twenty minutes, give or take), so let’s talk about the plot framework that surrounds it – and, specifically, why Fifty Shades starts to hit diminishing returns around its midpoint. There’s not too much plot to discuss, to be honest; Anastasia Steele (Johnson) and Christian Grey (Dornan) conduct an unconventional romance after the former – an English lit student – interviews the latter – as discussed, a self-made millionaire. Christian wants to control Anastasia; specifically, he wants her to sign a contract to become his live-in sex slave.

The main dramatic thrust of the film revolves around that contract. The proposition put to Anastasia is clear: sign the contract, and accept punishment (whips, bondage and the like) if she transgress Grey’s rules – whether it’s touching him without his permission or rolling one’s eyes. What she gets in return? Grey himself. And all the helicopter rides and fancy cars and ultra-modernist apartments that goes with the man. But Anastasia is virginal, innocent, romantic, so she demands dates and dinner with the family as part of her negotiation. Critically – and, I suspect, in sharp contrast to the source material – the film acts as a framing of consent, and whether or not Anastasia will grant it.

Not that consent precludes their ‘relationship’ trending towards abuse. Grey may not ‘punish’ Anastasia without her explicit consent, but the way he pressures her into signing said contract is decidedly creepy. He monitors her, he manipulates her, he uses his wealth as unspoken leverage (as when he buys her a brand new sports car as a ‘graduation present’). He controls her. In many ways, their interactions operate like the courtship preceding old-fashioned marriage; once the man wins the trust of the woman, he ‘owns’ her. There’s a skerrick of social criticism here, criticism provided by that perspective I was talking about earlier, but it falls away in favour of generic relationship troubles in the last act.

Here’s how I expected things to go down: Anastasia makes the decision to sign the contract, before realising that what she’s got herself into is not something she’s ready for – and not something so easy to escape from. This would’ve tied neatly into the marriage metaphor and a criticism of patriarchal pressure on young woman to conform, as well as amp up the dramatic tension.

Instead, we go a different direction. This isn’t necessarily bad – it’s nice when a story surprises you – but the decision to drag out the argument between the couple makes the back half feel both repetitive and thematically hollow. The sex scenes aren’t as sexy. The bad dialogue earns sighs rather than laughs.

I’m not going to pan Fifty Shades of Grey. While the sense of perspective granted to it by the medium of film isn’t leveraged as well as it could, it’s far from a disaster. It’s refreshing to see a film written by a woman, directed by a woman and featuring sex scenes that are sexy without being exploitative. It could have been so much more, and I can’t really recommend it, but nor is it deserving of the derision directed its way.