Is this normal?

At our house Gray is known as Fancy the dog, thanks to my friend Kellie who named her dog with such a girly(is that a word?) name:) Anyway, I let him crawl around the house, act like a dog even when we are at other people's homes or in the cart at the store. I figure he has a fun imagination and I should let him be a kid. However, he threw a massive fit yesterday when asked to eat his cereal at the table and act like a big boy and not a dog. He insisted that he would not eat unless he could eat like a dog. This went on for an hour until finally I gave up. Not quite sure what to do with this one!