There is no single "first kiss in the world," but there are scientific and archaeological records: scientists suggest that kissing on the mouth emerged 20-21 million years ago among ancestors of great apes, while archaeologically, the cave paintings of Serra da Capivara (Brazil) show the oldest kiss in human history (approximately 12,000 years ago).

So, the first kiss register is a Brazilian one from Serra da Capivara, in Piauí state.

O primeiro beijo registrado do mundo é brasileiro! Que orgulho! xD