Place it right after the surprising reveal, before the group reacts, then follow it with the Bruh sound for a second beat and the Oh My God meme when the joke escalates further.
About this sound
This is a very short Japanese voice clip, lasting about half a second, in which a speaker stretches out the word for 'what is it?' with a rising, puzzled tone. It feels confused and a little suspicious, like someone has just heard something that does not add up. The clipped delivery makes the reaction land instantly, before the listener has time to explain.