What should i do about my cat ......?

hes 10years old i never had a problem with him comming in my house to eat untill i got a baby kitty 6 months ago and he was ent havent a problem till reasantly he now sits out my moms door and crys till she feeds him but she dont wanta feed him what do i do he wont come in any more and when i feed him outside the skuncks and other cats eat his food any ideas