Put it at the exact point where the mistake is revealed, after a short build-up, then follow it with Awkward Crickets Sound Effect to let the embarrassment hang before cutting to the next scene.
Über diesen Sound
This is a four-second Swiss German voice clip of someone shouting “Du huere verdammte Schafseckel,” a harsh insult aimed at calling another person an idiot. The delivery is loud, sharp and instantly confrontational, turning sudden anger into something funny when the target has clearly done something foolish. Its force lands even before the words are understood.