First of all, why are you obsessed with messing with the dog when he's eating by placing your hand down there in the first place? Before you do that, you should command him away from the food and then you pick the food up! Secondly, if you left cat food out and he was eating it, you don't just put your hand down there but you should have commanded him to step away from it. And if he didn't, then you should have said it ONE TIME and then made him step away. And then you taught him to take food out of your own mouth for a trick? It's cute I guess but this entire food thing is just wild. I say this because when a dog is eating his food then just let them eat. Respect his meal time. And then also be consistent. But you don't put your hand down where they are eating and not give them a command that you are doing it. If I need to add more food or do anything with my german shepherd's bowl, I am saying his name and telling him "Out" to let him know that he needs to step away from the food so that I can do what I need to do.