Place it immediately after the repeated line in a short reaction edit, then follow it with Okay Let's Go to keep the exchange moving, or cut to Nope when the repeat makes the claim even less believable.
关于此声音
This short Flowery voice clip from Deltarune Chapter 5 lasts under two seconds and delivers the line 'Say that again' in the character's distinctive voice. It feels playful and slightly teasing, like a light challenge to repeat something surprising or suspicious. That brief, direct delivery makes it easy to recognise and fun to drop into a reaction.