Place this clip as the reply beat after the questionable claim in your edit, then follow it with the oh no no no laugh for the payoff. For a drier cut, end the sequence there instead of adding another reaction, so the accusation stays as the final editor's note before the next scene.
关于此声音
This is a short spoken clip, just under five seconds long, delivering the Russian phrase 'Esly ya obmanivayu,' meaning if I am lying. The line is delivered plainly as a single voice statement. It gives an awkward, caught-out feeling, like the moment a bluff gets questioned and everyone waits to see if the speaker doubles down or backs off.