I understood his question completely, as I have a friend who also spoils her child, gives him everything, and doesn't take advice very nicely at all. He throws temper fits in public places, NEVER finishes his meals (usually hits his mother with forks or knives while she tries to eat), and is allowed to destroy items in the homes she visits because she doesn't think he'll do so.

MY advice is to NOT bother giving such a person advice anymore. They will only blame you for pointing out their faults, get angry at you, and then because they are really angry at _themselves_ they will do the opposite of what you advise them to do. You cannot win giving such people advice. Simply tell them that that you would feel better not giving advice and/or any advice you might give wouldn't be appropriate or received gladly as that is not your child (hopefully?). :)