I don't have much advice for you sweetie but just wanted to say that you're not alone, Moo has been much the same lately. It's mostly directed at DH and myself but he has pushed and kicked poor little Alex too.

I try not to make a big deal out of it, and I don't discuss it with DH in front of him now in case that was validating him more. I'm at a bit of a loss atm though as nothing really stops it.

Lately I've just been saying that hitting people isn't very nice, when we hit Alex he gets scared and it's not nice to be scared etc etc. I've also been making a huge deal out of him when he does something that's helpful, as well as telling Alex that he way too little to play/eat/go blah blah blah, in the hope that Moo will feel like he's getting/doing more itms.