The acronym "FAFO" stands for "F*** Around and Find Out." It is a slang phrase used to warn that actions have consequences, meaning if someone messes around or causes trouble, they will eventually face the results of their behavior. This phrase is similar to sayings like "If you mess with the bull, you get the horns" and has gained popularity especially on social media platforms recently. It originated from African American Vernacular English (AAVE) and has been used in various contexts, including political discourse and internet culture.

Additionally, "FAFO" has been adopted as a no-nonsense expression in parenting circles, emphasizing letting children experience the consequences of their actions naturally.