Because he knows you are so loyal he will start DEMANDING that you do things you don't want to do.
Do you? After all he is used to your rolling over at everything already. You have set the precedent for him because y'all have given him CARTE BLANCHE to do or say whatever the he** he wants and you defend him.
So what if he tells you that he has to be the beneficiary of all insurance policies> That you must leave all your worldly goods to him or one of his trump progeny? Would you comply with that? You think it is absurd? Really/ You give an inch to a guy who takes a mile without your permission and keeping giving. What makes you think he will stop at anything to get everything he can from you and others like you?