Place it right after the wild admission in your edit, as the punchline reaction, then follow it with Kiko Laugh for a second reaction from another character. Keep the confession audible first, so the two reactions land as a back-and-forth instead of a pile-up.
About this sound
This is a just-over-a-second burst of wild, rolling laughter, spelled out as 'ééheheehhehhheée', with the speaker sounding completely unhinged and amused by himself. It feels funny and slightly deranged, like catching someone mid-cackle at their own joke, and it carries the tag 'é eu to loco', meaning 'it's me, I'm crazy'.