Place this clip immediately after the offending line in your edit, then follow it with a bruh meme beat for the embarrassed pause. For a stronger sequence, let the scolding play first and save a fail sound for the moment the speaker gives up arguing back.
About this sound
This is a short 1.9-second voice clip of Robin delivering the Portuguese line 'modere o linguajar,' a firm telling-off to watch your language. It lands as funny and mock-serious, like a superhero sidekick suddenly acting as the group's strict moderator. The clip comes from Feira da Fruta, the Brazilian dub parody where that scolding became a repeatable reaction.