Pecado translates to "sin". This word is the central theme of the song, which gets its title from the biblical story of Adam and Eve.
Paulo Londra uses it to propose a secret, forbidden romance, singing, "Como Adán y Eva, tengamos nuestro pecado" (Like Adam and Eve, let's have our sin). It's a powerful and evocative way to describe a love that feels both wonderfully tempting and a little bit wrong.
This song is all about a guy finally getting the courage to talk to his crush. He sees that she's in a relationship with someone who doesn't appreciate her, singing, "él no te valora" [he doesn't value you]. He's been watching her from a distance, calling himself "solo un cobarde más" [just one more coward], but tonight is the night he makes his move. He's not holding anything back, declaring, "Esta noche no me guardo las palabras" [Tonight I won't hold back my words].
His big proposal is pretty dramatic and romantic. He suggests they start a secret, forbidden relationship, using a famous story as his pickup line: "Como Adán y Eva, tengamos nuestro pecado" [Like Adam and Eve, let's have our sin]. He also compares them to "dos ladrones, un secreto bien guardado" [two thieves, a well-kept secret]. It's a song about taking a risk for a love that feels destined, even if it has to start as a secret.