Place it just after the smell is revealed in your edit, then follow it with Eww Brother Eww for a second reaction before cutting to the next scene. For a bigger payoff, put Oh My God Wow before it so the surprise builds into the complaint.
About this sound
This is a short two-second Portuguese voice line in which a man bluntly announces that something nearby smells of shit. The flat, fed-up delivery makes the disgust feel immediate and comic rather than angry, perfect for calling out a bad smell with exaggerated disdain. It was recorded from a clip by the channel Kesyn & Skelter.