Mentiroso is the Spanish word for liar, and this clip comes from Enrique Iglesias singing it in his Spanish-language pop song of the same name. The single word works on its own because the vocal delivery is so exaggerated, making it easy to lift from the song and reuse as a standalone reaction. Online, it circulates mainly as a short audio meme for calling out dishonesty, often in Spanish-language edits and bilingual videos where the meaning is clear from tone alone, even without translation.