Something you might say after you say something to someone and they say 'what?' and you don't know what they said what at.
Me: Hey yesterday I cycled my bike out the roof and then landed on top of my math teacher. It was painful but funny.
Someone else: What?!
Me: What are you whatting at?
Me: "Have you ever wondered if you bought the same milk from the same cow?"
Friend: "What??"
Me: "What exactly are you whatting about? I'm the one who asked a questionfirst."