The line is a common Brazilian Portuguese expression used when two people share knowledge they would rather keep hidden, and its blunt mention of the devil gives it an exaggerated, joking weight. In this clip form, credited to Sgt SemCalmante, it spread as a short reaction audio through meme pages, messaging apps and edited videos in Brazil. Creators reuse it as an instant caption for gossip, secret plans and caught-in-the-act moments, because the familiar phrasing needs no explanation for Portuguese-speaking audiences and the short length fits quick cuts.