Where does he get this??

I can't believe my Little Prince Charming just told me to "shut up" when I told him to stop jumping on the bed! I'm heartbroken! We don't talk like that in our household so I have to wonder where he's picking it up. I told him if he says it again he loses his Harry Potter privileges. He didn't like that at all, and I don't think it's nearly harsh enough, but he is only 3 years old.