Place it at the end of a setup line, then follow it with the shocked meme sound for the reaction and the why are you running sound if the joke turns into a chase.
このサウンドについて
IWBYFA is a very short 2.2-second sound built around its four-letter name, delivered in one quick burst that is easy to recognise once you have heard it. It feels blunt, cheeky and deliberately abrupt, the kind of clip that cuts through a conversation and makes a room pause for a beat. Its brevity is the point: it lands, gets a reaction, and is gone before anyone can answer back.