Light YTA. He is Chinese, wether you think he’a not practicing his culture enough doesn’t change the fact that is part of his identity. And to be fair most of the stuff you have for your wedding isn’t just for you, it’s for your guests and parents. Why is it wrong for him to want to do something culturally important to his father? Is it a crime to want to make your parents happy by embracing your culture? Maybe you think he’s doing it for the wrong reason, and maybe he is, but you just suspect. Maybe he’s jealous of his fathers approval toward his brother and he wants that same recognition. Doing something important to his father is a step towards that. And a wedding is also not just a you thing. It’s for both of you. And if this is way he wants then why can’t you make that concession?