My fianc and I are planning on having a very intimate destination wedding next month. We sent out save the dates and lists of local hotels over 9 months ago and let guests we planned on sending only 25 invitations know that due to the small nature of the wedding, we will not allow plus ones unless we know the extra guest very well. We sent out our invitations a few months ago very clearly labeled with guests names and without plus ones, but the best man returned his RSVP at nearly the deadline with a plus one penciled in. After days of him trying to argue with my fianc about how unfair it was that he couldn't bring a girlfriend hes been dating for a few months that we have never even met our final count is only 20 guests, he said he would no longer be attending the wedding. What would have been the best way to handle this situation?