Contrato means "contract." While it might seem like an everyday word, its use in this song is particularly interesting because the artist explicitly states, "Y así no haya un contrato, bebé" (And even if there isn't a contract, baby) and later, "no quiero un contrato" (I don't want a contract).
This highlights a tension between formal agreements and the informal, passionate nature of his relationship and lifestyle. It suggests a love that transcends conventional commitments, making the word "contrato" a central theme that defines the unique dynamic of the song.
"Contrato" starts with a goodbye that isn't really one: 'Sabes que me voy' [you know I'm leaving], 'Pero no es para siempre' [but it's not forever]. Nanpa Básico spends the whole song explaining why she should believe that, even though his job means he's gone more than he's home.
The title is the joke and the point at once. He tells her 'Y así no haya un contrato, bebé, que ante nuestro amor' [and so there's no contract, baby, before our love] - nothing signed, nothing legal, just him saying it. Instead of a ring or a promise he can't keep, he asks her to leave 'un poco de tu olor' [a little of your scent] in his clothes, something small enough to carry on tour. By the time he gets to 'Si alguien te daña te juro lo mato' [if someone hurts you I swear I'll kill him], he's clearly overselling it, but that's kind of the charm: a guy who can't offer stability is instead offering everything else he's got.