WYO in texting usually means What You On? a casual way of asking what you’re doing or what your plans are. For parents, it’s not something to worry about on its own. It’s common slang among teens and generally harmless. However, like any casual messaging phrase, it can sometimes be used in conversations with strangers, so it’s still a good idea to encourage kids to be mindful about who they’re chatting with and to practice safe online communication.