@hideki In the New Guinea tribe of the Simbari they take boys who show signs of puberty to the ritual semen drinking hunt, where the boy must ingest semen orally and anally through copulation in order to become a man. It's all relative. In frontier days families lived in on room, and kids would often see their parents fucking. In Victorian England a mother couldn't even hug her son for fear of impropriety. It's all relative.