I'm not going to pay for my sister's husband's dinner tonight at her birthday party.
Is there a reason that you do not want to pay for his meal?
I don't like him and I think he is greedy
You not liking her husband is fine and It shouldn't be expected for you to pay for his dinner at your sister's birthday dinner. That doesn;t even make sense. It would be pretty rude for him to expect that from you.
I'm going to take this to a manager and make a big deal about it.
Maybe you all should just split the bill equally. You should not be responsible for paying for the entire dinner.