Try changing your tone of voice. Clearly he finds something about your response amusing. Try not reacting with any emotion. Be very monotone and don't yell, etc. No animation basically. It's bound to get dull once he realizes he can't get a rise out of mom. Otherwise, I think you're doing all the right things. It's a frustrating age because he's doing all the things he's supposed to do -- push boundaries, discover, etc. -- and if he weren't doing this in the first place, that wouldn't be a good sign. I know someone here is going to recommend spanking or hitting with a stick. Frankly it flabbergasts me that people still rely on these things despite good evidence pointing to how it doesn't work. That's not discipline in my book. Kids learn by example and that sets the wrong example. Yes. You are the boss, but you're also his greatest role model and he will model after you. Dr Sear's Discipline book is good and so is Happiest Toddler on the Block. You might look into those if you're interested in learning more about his behavior and how to deal with it. Also, google the term "positive parenting". There are loads of books and resources available.
Good luck! I know how frustrating it can be. But I think you are doing the right thing. It just takes a while for it to sink in.
