Place it right after a failed attempt in your edit, then follow with a no no wait wait reaction if the scene keeps spiralling, or switch to a wrong answer game show sting for a quiz-style fail.
Über diesen Sound
A short voice clip of a speaker blurting out the Portuguese line 'Essa eu não ensaiei!', admitting this one was never rehearsed. At just over a second and a half, it lands as a quick confession of being caught unprepared. The feeling is flustered and funny, like improvising on the spot after a plan falls apart in front of everyone.