I am seeking impartial opinions from both ladies and gentlemen:
Jk, yes, it was very inappropriate.
Clearly your husband is the problem. He's never cut the umbilical cord and he has no other model for parents so he thinks his mother's behavior is "normal."
He's either going to figure out he needs to put your first and treat you accordingly or not. If he can't do that with marriage counseling and grow a backbone now, he never will.
Why in the world did you even marry this man after the few holidays that were completely insane?
Your mother in law is nuttier than a fruitcake, and your husband is just as bad.