This is really for weddings, funerals, feast-days, other ceremonies and holding court in general, but I feel it is really easy to see the trend across media in how capital-D Dinner is presented. If you've actually been involved with wedding planning, you have my sympathies but you will also have excellent advice for making this move better.
When you call for a Dinner, first choose who is invited and who is not; then roll +Cool.
On a hit, any invited NPC that can make it, will make it. On a 10+, choose one:
> you may Claim Your Right, as though rolling a 10+, to an Oath from any or all the attendees
> you may trigger the Want of any or all the holdings, supporters, etc, of those that declined your invitation
> you up the conviviality to the point of indiscretion, giving all attending +1 to Draw Someone Out and -1 to Take Stock while Dinner continues
If you are clearly connected with violence that occurs at your Dinner, no-one is required to attend your Dinners and you cannot get a 10+ until you clear your name.