Place it immediately after the mistake is shown, so the insult answers the action on screen. Open the sequence with SpongeBob Fail to flag the blunder, then let grandma respond, and close with Vine Boom for a final beat.
About this sound
This 2.4-second voice clip features an angry older woman snapping 'you stupid-ass' in a sharp, exasperated tone. It lands as a blunt, funny telling-off, the kind of scolding that makes a dumb mistake feel instantly called out. The delivery is direct and confrontational, leaving the listener laughing at the audacity.