“Fifty Shades of Grey” is a two-hour tease with no climax. (Insert whatever sexual joke you want here.)

The film ends so abruptly and unexpectedly that most of the audience at the preview screening I attended seemed more bewildered than anything else. I swear I could hear Peggy Lee singing in my head “Is that All There Is?”

The answer is, unfortunately, “yes.”

Related: Russell Wilson defends seeing ‘Fifty Shades of Grey’

This movie, of course, is based on the insanely popular trilogy of books by E.L. James. She is often credited with bringing S&M into the mainstream. But if that’s true, it also appears the mainstream has, in return, diluted most of the kink out of this alternative lifestyle.

This first of a projected three-movie deal is so tame it’s barely recognizable as S&M. That’s not to say there’s no sex in “Fifty Shades.” There are three or four legitimate sex scenes but they’re all handled so tastefully, and so discreetly, they barely register as “outside the norm.”

If it’s possible to have vanilla S&M, then “Fifty Shades” is pure vanilla extract.

The plot is standard fairy tale material: an unremarkable young woman finds herself the object of desire by a man far above her station. (Think Cinderella, or the Twilight novels, which directly inspired James to write in the first place.)

The Prince Charming in this case is a 27-year-old Seattle billionaire named Christian Grey who’s inexplicably drawn to a virginal and klutzy English major named Anastasia Steele. She’s equally drawn to this smart, handsome, impeccably dressed man of mystery who exudes power and confidence from every pore.

They happen to “meet-cute” when Anastasia interviews Grey for her campus newspaper.

One thing leads to another and eventually they end up in bed together, but not before he explains to her that he “doesn’t do romance.” What he does do is introduce her to his playroom, aka the red room of pain.

What she sees is a gorgeously decorated room full of all the accoutrements a practitioner of S&M could want – lots of lovingly displayed whips and floggers, padded leg and arm restraints, ruby-red nylon ropes and pitch-black blindfolds, and of course, a comfy king-size bed.

These items are indeed incorporated into their lovemaking – scratch that, Grey doesn’t make love, he explains, he only “bleeps” – but, for the most part, they’re used so gently they almost seem irrelevant. In fact, the movie’s sexiest scene involves not some kinky device but a simple, unadulterated ice cube.

Grey eventually gets around to explaining that he’s a dominant and he wants Anastasia to be his submissive. In fact, her duties are all laid out – in explicit, sexual detail – in a legally binding contract he wants her to sign. The only real tension in the movie arises over whether Anastasia will agree to his demands or not.

To sign or not to sign. That is Anastasia’s dilemma, and she’s surprisingly coy about it. In one of the film’s best and funniest scenes, she sits across the table from Grey and goes over the contract line by line accepting and/or objecting to various sexual practices outlined in the contract.

For a potential submissive, Anastasia is a surprisingly powerful negotiator. Even after all his concessions, she’s still undecided about signing. It turns out the most interesting aspect of the movie is not the sex but the power struggle between the two characters. The problem with that approach is that neither of the characters is fleshed out enough to make that work as drama.

Besides, power struggles don’t sell tickets like transgressive sex can, so we get a classic case of bait and switch.

Buyer beware.