So our RSVP date has come and gone and our venue needs a firm number from us very soon. We have heard from everyone on my side of the family, but we have about 20 people on my FI's side who have not responded. We've tried calling (lots of disconnected phones, or we leave voicemails and get no response), e-mail, Facebook, EVERYTHING to try and get in contact with these people, but to no avail. His mother and sister have told us that these people tend to be flaky and they aren't surprised (but aren't being particularly helpful about it either). I'm at a loss at this point! Should I just call or e-mail again and inform them that since I haven't heard from them I'm marking them down as a no, so we won't have a seat for them? Is that rude? As much as it annoys me that these people are being so flaky, I would like them to come because I feel bad for my FI (I have about 70 people coming, right now his side adds up to some friends and his very immediate family). What should I do?