Place it just after the bite is shown, then follow the accusation with a fart with reverb for the payoff, and finish with a scream meme when the eater realises everyone is watching.
關於此聲音
This roughly ten-second Japanese voice clip catches someone calling out Unko Man in the middle of eating poop, first urging him to eat plenty because it tastes good, then reacting in loud disbelief. The gross, over-the-top callout feels silly and shocking at once, like a playground accusation shouted for laughs.