The idea of a 'Mario Sex Education' game is a persistent rumor circulating online. Despite its widespread discussion, there's no evidence to suggest that such a game actually exists or was ever officially developed by Nintendo. The rumor likely stems from the internet's tendency to create and spread fictional content, often with the aim of shock value or humor. While unofficial and fan-made games may exist containing mature themes, there's no legitimate 'Mario' title focused on sex education. It's crucial to verify the credibility of sources before believing in such claims, as they are often designed to be misleading.