Place it right at the reveal in a funny edit, after a sudden suspense sting builds the tension, then follow it with Nelson's Ha-Ha! to underline the joke for a quick payoff before the next scene.
About this sound
This short clip plays the chorus of Erasmo Carlos's song Pega na Mentira, lasting about eight seconds with a warm, melodic vocal line that repeats the title phrase. It feels playful and knowing, like a lighthearted nudge when a fib slips out, and it comes from the Brazilian singer's song of the same name.