Was Decker a rescue kitty?? Someone might have already asked you this but if he is he might not realize that he has a NEXT meal and it may just take sometime for him to realize that you will always feed him and he doesn't have to settle without a meal. I have had some of those problems with my male cat Tucker he was VERY protective of his food at first and to this day he still has to eat first and he over eats which in return makes him throw up. So I have those issues also I would hope the aggressive behavior might be the kitten in him but like I said Tucker had some issues but he still eats till he is sick so I think its attributed to the Alfa male in him that makes him do that. He has gotten better but he still eats as if its his last meal. Once a cat goes through that they seem to never forget. Hope that helps????