Place it right after the smell is revealed in the scene, then follow it with Eww Brother Eww to keep the reaction going, and finish with Oh My God Wow when the room reacts together.
About this sound
This is a two-second spoken reaction built around the line 'You're lettin' the stank out,' delivered as a direct call-out to someone whose smell has just escaped into the room. It lands with playful disgust, sharp and teasing rather than angry, making the awkward moment feel lighter and funnier for everyone listening.