It’s the aim – or it should be – of every youth-oriented horror or thriller to capture with authenticity the moment when the party mood drops. The silence just before the first scream; the dissonance that occurs when noises of enjoyment still sound over an increasing hushed awareness that something really bad has happened...

In Donkey Punch, the party is wild, and its ending brutal. Tammi (Nichola Burley), Lisa (Sian Breckin) and Kim (Jaime Winstone) are on a flashy, hedonistic Mallorca holiday when they meet some smooth-talking British lads, and – clearly never having seen Knife in the Water or Dead Calm – agree to an ill-fated spin on the yacht they’re crewing.

Though it certainly punishes the ill-behaved, this slick, disturbing thrill ride enjoys its splatter violence and its lingering group sex scene rather too much to be classed as a morality play. Still, the grisly sex act that gives the film its title is a sick joke on a porn-saturated society: if sex is divorced not only from reproduction, but from every cherishing instinct, it becomes a destructive, even a lethal drive. Raised in a culture in which images of the most extreme sexual acts are a mouseclick away, and vicious criticism of women’s bodies is a popular bloodsport enjoyed by both genders, the young women played by Winstone and Breckin connect their own value with physical display and sexual adventurousness. (Only the more reserved Tammi, portrayed with insight by newcomer Burley, notes the gestures of triumph that pass between the boys as they take their conquests below deck.)

The extremity of the content is lent credibility by the conviction of the performances, and the attention to bang-up-to-the-minute detail. The girls’ spangly beachwear is straight out of the airport Accessorise, the male ringleader Bluey’s terrible cockney/patois/posh boy accent is irritatingly familiar, and Kim does every Heat reader proud when she finds time during a bloody life-or-death struggle to sneak in a comment about Tammi’s weight.