The phrase is Portuguese for how romantic, and this clipped version circulates as a short reaction sound on soundboards and in chat audio shares. Its appeal comes from the contrast between the sweet wording and the exaggerated guauu that follows, so it is used both sincerely for cute couples and ironically for cringe or staged romance. Because it needs no context beyond a visible romantic gesture, it travels easily across edits, stories and group chats where a quick teasing reaction says more than a typed comment would in that moment.