I dont want to buy extra plates since my parents have decided to pay for the whole dinner, drinks and midnight supper. Is it rude to put a sign up at the reception saying if they didnt rsvp they dont have a seat? Or should we message personally on Fb/email that if you didnt rsvp you wont have a spot but more than welcome to come for everything but dinner? Please help! I feel bad but i cant wait any longer.