FI and I were stuffing and stamping invitations last weekend and he mentioned that the H of one of his mother's friends would be unable to attend, but that FMIL extended the invitation to another of her girlfriends instead. We sent STDs a while ago, all of these guests in question are OOT, and we addressed invitations by specific names. Is there anything wrong with FMIL inviting and allowing her friend to bring another friend as her "date"? The addedon friend is also married, but I guess FMIL's invitation does not extend to the H. It doesn't bother me, since the net total remains the same, but I wasn't sure if it is rude to essentially B list a friend who didn't make the initial guest list.