Aai meu deus is a Brazilian Portuguese exclamation that translates to oh my god, and this clip became popular online purely as a reaction sound rather than as a quote from a known film or show. Short voice notes like this spread through messaging apps, group chats and meme edits because they are easy to reuse out of context. Creators keep returning to it because the stretched, desperate delivery works for almost any kind of shock, from genuine surprises to deliberately overreacting to something trivial for comic effect.