L.W.
B.,
As everyone else has said, this is VERY NORMAL behavior. (I have 4 sons and the youngest isn't quite to this stage yet, but he's getting there.) Your son is just testing the boundaries. Continue to be firm and consistent. He needs to know what will happen if he acts a certain way. It is also part of feeling secure, knowing what the consequences of his actions will bring. This is part of natural development, even though not every child acts in exactly the same way. Stand firm now, and you won't have all the problems later when he is a teenager.