You probably take more things away from him than your bf. If your bf keeps moving his bowl while eating it'll just be a matter of time before the pup growls at him too. Then when the growls aren't enough to keep you away he'll bite. Not a friendly mouthing bite but a real serious get away from my food bite..
It needs to be fixed immediately and testing the dog by messing with his food isn't helping. In the search bar above search for resource guarding