Place it right after the wild claim in your edit, as the direct reply, then follow it with Bruh for a second reply and Emotional Damage when the speaker doubles down instead of backing off.
About this sound
This is a short spoken Russian line, lasting about six seconds, delivered in a flat, unimpressed voice as the speaker brushes off nonsense. It lands as dry, exasperated disbelief, the kind of reply that makes a wild claim sound ridiculous without raising your voice. The bluntness is what makes it funny, especially when the other person is clearly making something up.