Close to Leo (2002)

When 21-year-old Leo, the oldest of four brothers, announces to his rural French family that he's HIV+ family bonds are tested. The family decides that 11-year-old Marcel, the youngest, is too young to understand, and the family agrees to keep the unsettling news from him. Marcel overhears enough to understand that something amiss with Leo and when the two travel to Paris together, Marcel confronts Leo with what he suspects.