Place it right after the on-screen mistake, then follow with the wrong answer game show sound for a judged fail, or add Nelson's Ha-Ha! afterwards if a friend is doing the mocking in the edit.
Über diesen Sound
This is a short voice clip, about three seconds long, of Mosquiil saying 'I blew...' and letting the line trail off unfinished. The delivery feels sheepish and caught out, like admitting a mistake right after making it. That half-finished confession gives it an awkward, funny sting.