Co-written by Cuaron's brother Carlos Cuaron, Y Tu Mama Tambien operates on two entirely different levels. On its surface the film is the story of two male high school friends off on an adventure with an older, married woman that will forever change their lives and their relationship with each other. Tenoch (Diego Luna) and Julio (Gael García Bernal) grew up together in Mexico City and have been friends since childhood. They are both handsome, smart, sexually experienced, and nonetheless very much still in the process of becoming. In this last regard they are cautiously wild, if such a consciously paradoxical description is understood to mean that they are open to various kinds of experimentation with sex, drugs and attitudes, so long as a path of retreat remains clear and close by.
Despite such similarities, and despite the apparent strength of their friendship, Tenoch and Julio are actually from very different places. Tenoch is the son of a Harvard-educated economist who has risen to the highest levels of Mexico's socioeconomic/political world. Tenoch's father is the kind of man who gives parties attended by the nation's president. Julio, in contrast, is a child of the lower middle class. His mother is a secretary, and his father disappeared when Julio was 5. Tenoch, moreover, is fair-skinned, a Creole Mexican child of pure European blood, while Julio is dark, a Mestizo, a child whose ethnic heritage is presumably as much native American as European.
When Tenoch's and Julio's girlfriends both head off to Europe for the summer, the two teens are left to self-gratification until they convince 28-year-old Luisa (Maribel Verdú), the wife of Tenoch's cousin, to accompany them on a road trip to a mythical Pacific Ocean beach. Luisa is not quite the elite princess they think she is, despite her husband's political and professional connections (he's a university professor). A native of Madrid only recently and still uncomfortably arrived in Mexico, Luisa is a dental technician always ill-at-ease in her husband's intellectual world. Still, it's his infidelities that send her off with two teen-agers. Along the way the three become friends, confidants and ultimately sexual partners as well. But don't for a second mistake this film for a Mexican version of Losin' It.
For all around the edges of what pretends to be a randy sex comedy are somber images of worrisome reality. Though the action never points to the roadside, the travelers are forever passing through armed roadblocks where peasants are being searched and bullied by rifle-toting soldiers. At the beach the threesome are graciously assisted by a fisherman whose future, we are told, is grim. His fishing grounds will shortly be appropriated by a luxury resort complex, and he will spend the rest of his life as a janitor.
Gradually we come to understand that Cuaron has built his tale as an elaborate allegory about Mexican history and society, and in that recognition we grasp why we have liked the principals in the film so little and found their sexual escapades discomfiting rather than arousing. Tenoch's father had intended to name him Hernan for the Spanish conquistador and plunderer Cortez, but chose an Aztec name for him at the last minute. Such a disguise evokes the oligarchic domination of Mexico for most of the 20th century by a political party calling itself "revolutionary." Tenoch starts out wanting to be a writer, an artist, the creator of something new. But his father is a man once indicted for selling tainted food to the poor, and in the end, Tenoch is his father's son.
The film's last scene is an undefended left hook to the jaw. Events on the road trip have brought class distinctions out in the open. But the boys meet for coffee to talk about the summer past and their college careers now undertaken. Like so many of the Mestizos who have benefited from their allegiance to the Spanish Creoles, Julio has had experiences unavailable to the Native American peasantry. But the Spanish connection that has brought them together is corrupt and now both figuratively and literally dead. And on this day, as for all time, it's the Mestizo who pays the bill.