Place it right after the bad suggestion lands, then follow it with the Bruh sound for a deadpan finish, or put Emotional Damage after it when the rejection needs to sting more.
About this sound
This clip repeats the German word for no four times across about six seconds, each Nein stretched longer and delivered with rising desperation. It sounds like someone refusing harder with every attempt, turning a simple answer into an over-the-top protest. The effect is funny and emphatic, perfect for a flat refusal that still needs to feel dramatic.