Place it right after the reveal shot, at the moment the stare lands, then follow it with Bruh for a flat reaction or Emotional Damage when the joke turns on the person caught looking.
このサウンドについて
An Mata is a short meme clip of just under three seconds, centred on its brief title phrase and meant to be used as a quick reaction. It feels playful and a little teasing, the kind of sound that punctuates a look, a pause or an awkward reply without needing a longer explanation.