Morderme la boca literally translates to "bite my mouth." While it might sound a bit aggressive, in the context of this passionate song, it's a highly intimate and sensual phrase.
Julieta Venegas sings, "Quiero ser la única que te muerda la boca" (I want to be the only one to bite your mouth). This isn't about pain, but rather a vivid and intense expression of desire and exclusive passion, implying a deep, almost primal connection between lovers. It's a unique and memorable way to convey intense affection and ownership in a relationship.
Julieta Venegas builds "Sin Documentos" around one image: crossing the wind without papers. "Déjame atravesar el viento sin documentos" ("Let me cross the wind without papers") opens the song as a request for a love with no borders, no permission slips, nothing to declare.
From there the song stays physical and direct: "Quiero ser la única que te muerda la boca" ("I want to be the only one who bites your mouth") and the plan to stick around — "Y mañana vendré con un cigarro a la cama" ("And tomorrow I'll come to bed with a cigarette"). But the hook keeps pulling back to something plainer than desire: "No quiero pasar más de un día entero sin ti" ("I don't want to spend more than a whole day without you"). The freedom in the opening line and the need in the chorus turn out to be the same thing.