Place it right after the moment someone is caught, then follow it with a shocked reaction or a burst of laughter to complete the joke. It works best as the turning point in a short prank clip, before a chase sound or a playful yell closes the scene.
About this sound
This is a short Portuguese voice clip, just under five seconds, in which a young-sounding speaker warns an auntie that they are going to tell their dad. The delivery is cheeky and dramatic, turning a small tattling threat into a funny, exaggerated moment. It feels playful rather than angry, like a child using the threat itself as the joke.