Place this clip as the final payoff after the setup joke, not under dialogue. Build toward it with the bark and fart sound first for a smaller gag, then follow the reaction with the Simon fart sound to close the scene.
About this sound
This is a 17-second clip of a guy making an extended, deliberately over-the-top diarrhea sound, presented in a louder version with a headphones warning. It feels gross, childish and shocking in a way that is meant to be funny, turning a normal moment into a complete toilet disaster played entirely for laughs.