I'm going to purposely tell my stepbrother the wrong time for christmas dinner
Why would you want to give your step brother the wrong time for such an important dinner?
I'm so sick of hearing his complaining about our parents every day. I don't want him over here.
You shouldn't mislead your stepbrother. Lying will just get you into trouble.
He better chill out if he wants to eat tonight.
With all due respect, it sounds like you need to be the one who should chill out. Making someone late to Dinner isn't the way to handle your issues with him, and you should instead speak with him about what's bothering you in private.