Place it right after the reveal shot, then follow it with a shocked sound for the first reaction and an oh no no no laugh once everyone starts joking about the smell.
このサウンドについて
This nearly 19-second clip is a heavily voice-changed Russian voice groaning 'fu, chem tak vanyaet' — 'ew, what smells so bad' — in a stretched, warbling tone that turns a simple complaint into a drawn-out gag. It feels funny and grossed out at once, like catching a terrible smell in a crowded room and having to announce it.