Estraga comes from the verb estragar, meaning to spoil, ruin, or mess up. It's a key word in the song's central theme.
The phrase "Ninguém estraga" (Nobody spoils/ruins) is repeated throughout the song, emphasizing the idea that if a relationship is kept private, away from the judgment or interference of others, it has a better chance of succeeding. It's a powerful word that captures the desire for a secret, unburdened romance.
Gusttavo Lima spells out the deal upfront: no serious relationship, something funny instead — "Pronto, eu não estou pronto" ("Ready, I'm not ready"). He'd rather laugh about his past with someone who won't ask what he did last night than sign up for anything real.
The chorus is where the whole arrangement gets its name: "E o que ninguém sabe, ninguém estraga" ("And what nobody knows, nobody ruins"). No promises, no showing her off at the club, no explaining himself to anyone else — just the two of them behind closed doors, and if he doesn't call the next morning, that's allowed too. It's a song about keeping something good by keeping it quiet, wrapped in a hook catchy enough to make secrecy sound romantic.