Place it immediately after a loud eating moment in your edit, following a cartoon munch and before an eww brother eww reaction, so the complaint answers the noise and the disgust closes the gag.
About this sound
This eight-second spoken clip is a blunt complaint aimed at someone chewing far too loudly, delivered in a fed-up voice that ends with a casual bru. It lands as awkward and funny at once, because the irritation feels instantly familiar to anyone who has sat beside a noisy eater.