Place it right after the reveal in your edit, then follow it with Oh My God Wow for a second reaction. For a bigger build, put Sudden Suspense just before it, so the build peaks before the reaction arrives.
About this sound
This is a short Portuguese voice clip, just under four seconds long, in which a speaker exclaims Meu Deus, que loucura! It gives a listener a burst of shocked disbelief mixed with amusement, as if something too strange to believe has just happened right in front of them.