"Don't copy me!"

We must hear the phrases "Don't copy me!" or "Mom! _____________ is copying me!" at least 4,826 times a day. What's hilarious to me is that all HATE IT when their sibling does it to them, but they still do it to their siblings. And it doesn't matter how many times we explain it to them- if you stop copying him, he'll probably stop copying you. It's definitely the biggest fight in our house.