Put it right after the bad reveal and before any reaction dialogue, as the first response in the edit. If the scene escalates, follow it with No God Please No for the bigger meltdown, keeping this clip as the initial shutdown before panic takes over completely.
About this sound
This is a 0.4-second voice clip of a single spoken word, nope, delivered flat and blunt. It feels instantly funny and dismissive, like a door slamming shut on an idea. The abruptness gives it a hard-pass energy that reads as refusal, disbelief, or someone deciding to back out immediately, with no explanation needed or wanted.