CANNES - Nothing I've seen at Cannes so far -- not even the current Palme d'Or favorite, Hirokazu Kore-eda's button-cute parenthood drama "Like Father, Like Son" -- has, to my ear, pushed the end-credits clap-o-meter quite as far into the red as Alain Guiraudie's Un Certain Regard entry "Stranger by the Lake." Elated whoops and whistles greeted this minimalist French thriller's final fade to black: not the reaction you'd usually expect from a civilian festival crowd for a work of such sleek, stark nihilism as to prompt visions of Robert Bresson adapting Patricia Highsmith. All of which leads me to at least one conclusion: audiences out there are really starved for gay sex.

Yes, "Stranger by the Lake" features more graphic man-on-man action on screen than you can, er, shake a stick at, granting it an immediate festival-world notoriety that will dissipate swiftly as many distributors simply cast it into the "unreleasable" pile. But while some will deem the film barely distinguishable from gay pornography, its surfeit of explicit sex scenes has a function beyond base titillation (though, let it be said, there's plenty of that too). If many films have put the practicalities and politics of casual sex to more rigorous examination on film in recent years, I either haven't seen them or napped through a lot of the subtext in "Hitch."

The setting -- from which the film never strays over a timespan of several days, lending proceedings an oddly airy claustrophobia -- is a picturesque lakeside cruising ground in rural France, frequented by a small but restlessly circulating crowd of gay regulars and holidaymakers, who turn up on a daily basis for a spot of (in ascending order of importance) swimming, sunbathing and al fresco shagging in the rough woodland behind the beach.

New to the scene is Franck (Pierre Deladonchamps), a handsome twentysomething more in the market for a partner than a sex buddy, but taking his chances in the meantime. His best chance, as he sees it, arrives in the form of Michel (Christophe Paou), an older, mustachioed swimmer on whom Franck becomes inordinately fixated. Michel is immediately flirtatious, though initially beholden to another sex partner; that only further stokes the younger man's desire, which doesn't waver even after, one balmy summer evening, he witnesses Michel murdering his mate in broad moonlight.

Franck tells no one what he has seen -- least of all Michel himself, with whom he willingly enters a steamy no-strings commitment, built on bareback intercourse and never leaving the confines of the cruising ground. The threat of murder proves a sufficiently powerful aphrodisiac for Franck to pursue a deeper relationship with Michel. Persistently rebuffed, he instead fosters a sexless companionship with chubby, closeted beach patron Henri (an excellent Patrick D'Assumcao), whose suspicions about the psychotic Adonis edge ever closer to the truth -- as do those of the police inspector who begins sniffing around when the corpse of Michel's last victim washes ashore.

This is already far too psychologically cumbersome to qualify as porn: porn noir might be closer to the mark, given how Guiraudie's stylish thriller framework plays the dangers of rough sex against its oneiric allure. One may choose to see Franck's outlandish fatal attraction as an allegory for more widespread hazards of homosexuality: if repeatedly hooking up with a known murderer doesn't kill him, having regular unprotected sex with a known player might do the trick in the long run. Not that Guiraudie and cinematographer Claire Mathon -- whose luscious, sun-dappled but eerily remote widescreen compositions plant the entire film in an uncertain Eden -- are passing judgement too harshly on these bronzed transgressors, nor those who delight in watching them. Hot and cold and provocative in more than just the expected ways, "Strangers by the Lake" presents even the most dishonest sex as an honest thrill.