You're sh*tty about it?
That's a bit much don't you think?
I'd be a bit upset but not sh*tty!
I'd arrange something another day.
A 21yr old doesn't really need a big family Christmas, they'd probably be more interested in having a fun time with a few drinks and chilling out, not tons of little kids and pretending Santa is real IYKWIM?
Just a heads up though, my mil used to get sh*tty at dh for silly things like this even though we always went out of our way to organise an event with them too.
We don't speak to her anymore (husbands choice) because her whiney and entitled attitude, and passive aggressiveness is too much to deal with, and not something we want our children exposed to.