Put this clip as the final beat after the reveal, not underneath dialogue, so the reaction closes the scene. Build up with the dun dun dun sound first for a failed moment, then let this hit alone, or follow it with the vine boom sound for a bigger second punchline in edits.
Über diesen Sound
The clip is a single short human vocalisation that sounds like 'buhh', lasting just under a second with no words or music behind it. It lands as flat, stunned and a little dumbfounded, the kind of blank reaction you make when something is too obvious or too ridiculous to answer properly.