At first this raw but sly Mexican comedy might make you wonder what the Spanish word for Porky's is, or wonder whether the film shouldn't have been titled Mexican Pie. But the Harold & Maude poster above the two naked high-schoolers energetically screwing in the opening shot, not to mention the arch voiceover narrator that intrudes at key moments à la Truffaut's Jules and Jim, suggests that director Alfonso Cuarón had more in mind than parodying crass Hollywood teensploitation. True, Tenoch (Diego Luna), scion of a corrupt nouveau riche, and Julio (Gael García Bernal), a raffish middle-class kid, share the occasional fart joke and masturbatory fantasy, but they have a bit more grit, taste, and imagination than their north-of-the-border celluloid contemporaries. So it's not impossible to believe that stunning Luisa (Maribel Verdu), the Spanish bride of Tenoch's prissy and adulterous cousin, might agree to join them on a trip to a beach called "The Mouth of Heaven."

The beach does not exist, but the Mexico along the way does, a catalogue of indelible characters and places put in sociological context by the omniscient voiceover. And the erotic tension among the three erupts in a ménage as startling in its dynamics as it is in its raunchy spontaneity. Much more about class, transience, desire, desperation, and mortality than about horny adolescents getting it on, Y tu mamá también nonetheless succumbs to that trademark Hollywood device -- punishing the characters for our guilt at vicariously enjoying their satisfaction. At the Avon.