What is a purple nurple?

A purple nurple is a slang term for a painful prank in which someone grabs and twists another person's nipple, causing discomfort or pain. The term is typically used in a playful or joking manner, but the act itself can be quite painful and potentially harmful. It is not recommended to engage in or encourage this type of physical contact as it can lead to injury or discomfort for the person on the receiving end.