Place it as the final line of a short fail sequence, after the mistake is already visible on screen. Follow it with a bruh reaction for a flat response, or swap that for an emotional damage sting when you want the embarrassment to hit harder.
About this sound
A short three-second voice clip of a speaker admitting they can't tie their shoes, then starting a 'but' that never gets finished. The unfinished confession feels awkward and self-deprecating in a funny way, because the boast that should rescue it never arrives, leaving just the basic skill they are missing hanging in the air.