The extraordinarily perceptive “How to Have Sex” pulls off many feats of daring: Nicolas Canniccioni’s alcopop-hangover photography, James Jacobs’ chemical club-anthem score, Mia McKenna-Bruce’s star-making central turn. But the most impressive is first-time writer-director Molly Manning Walker getting us not just to forgive her central triad their brash and brainless bravado, but to grieve for it when it’s gone. Set in Malia, on the island of Crete, “How to Have Sex” is a different kind of Greek tragedy — no grand myth, just a heart-sore, everyday observation of what the world does to girls and what the world makes girls do to themselves.

Tara (McKenna-Bruce), Skye (Lara Peake) and Em (Enva Lewis) are three teenagers whose trip to Crete has, in time-honored Brits-abroad fashion, absolutely nothing to do with the culture or history of Crete. They will not be visiting the ruins of the Minoan palace of Knossos. Instead, while they await their exam results, they’re here to get drunk, and to get laid — in Tara’s case, for the first time.

Hectoring their way into a room upgrade at their hotel, they spray on dresses over spray-on tans and go dancing and drinking. It’s a raucous night that ends in slurred affirmations of eternal devotion in an alley, their clasped hands slippery with French fry grease. But the next day, the faux-worldly Skye declares it a disaster, because none of them hooked up.

Mia McKenna-Bruce and Shaun Thomas in the movie “How to Have Sex.”

(MUBI)

So when Tara catches the eye of Badger (a superb Shaun Thomas) from the adjoining balcony (“Oi, smokeshow,” is his opening gambit), the girls accept the invitation to party with him and his mate Paddy (Samuel Bottomley), the cocky alpha to Badger’s goofy beta. Tara and Badger have a natural cozy chemistry: Her necklace spells “angel” in glinting gold letters; he has a neck tattoo of a lipstick kiss. But Skye, motivated perhaps by the sexual rivalry that salts the rim of many a female friendship, archly insists Tara can “do better” and encourages her toward Paddy instead. It leads to an encounter on the beach that Walker initially hides in her film’s only little fold in time, but that we come to know intimately as its every beat is replayed in Tara’s mind.

The ingenuity of Walker’s minutely-observed, lived-through movie, is that, beneath the strobe and neon, we cannot see the joins. We cannot accurately pinpoint the reason that Tara’s tiny, unconvincing “yeah” of consent sounds so unmistakably like a “no.” We cannot isolate the single guilty party responsible for the mounting disquiet she feels in retrospect, unease that clouds the close-ups of McKenna-Bruce’s pretty, glistening face and that can drown out the throb of dance music until all she hears is the surf and her own ragged breathing. Of course we can’t. That “yeah” was generated by a coercion that started long before Paddy’s insistent groping, long before the girls even came to the island, long before any of them knew what sex was, let alone how to have it.

But even if Tara realized that her “yeah” was generated by 16 years of immersion in a culture that talks incessantly about sex without ever saying anything useful about it, society is too big a target to scapegoat, and so of course, she ends up blaming herself, tamping her misery down under makeup and glitter and shots. Em pursues a lesbian flirtation. Skye puts the moves on Badger. Paddy brushes Tara off, until he creeps into her bed, interpreting that fraught “yeah” as an all-access pass without an expiration date.

For all its fizzing energy, this is a sorrowful film — sorry for the girls, sorry for the guys — keyed into the sadness that lurks in day-glo places, pool parties, dance podiums and the overlit cosmetics aisle of an airport duty-free. “How to Have Sex” is a story of loss, but not loss of virginity, nor even the loss of a sisterhood that seems more fractured with every new protestation of BFF-ship.

It’s Tara’s loss of faith in herself and the instincts that betrayed her, the loss of the happy dork who would rather hang with her friends or tell Dad jokes to Badger while he pukes in the toilet, than work so hard to attract the fleeting interest of a guy she’s been told is hot. It’s the loss of awe over what sex might be, how it might transform you. Instead, Tara learns the lesson that having sex is easy. It’s everything else that needs a how-to guide.