This will likely make people like your Brother-in-Law (who likely doesn’t want to be there with your family anyway) very happy with you….which isn’t a Bad Thing if he is a progressive, but will not make him very happy if his a a Conservative.
Of course, you could go all the way (Hey, if yer gonna make an already irritated Brother-In-Law go nuts, you might as well go all the way…..) and tell him that he HAS to take a double serving of cranberries even if he doesn’t like them, cover them with gravy even if he doesn’t want to (rules are rules, even when they make no sense), and charge him for the privilege. Say a hundred bucks. If he wants more, make it $150….explain that the “rich” need to pay their fair share…..
Then, of course, to really end the evening well, give him the entire DNC treatment: take 1/3 of everything he puts on his plate as a ‘Tax” (this also includes his liquor) and give it to someone else…preferably someone he doesn’t know. maybe a homeless guy waiting outside,,,
Charge him 60% of his dessert as a “luxury”. Even more if he wants a second helping
Only do this, of course, if you are brave….or at someone else’s house.