I know this is probably a petty thing to be worried about, but I just want to do everything right. If you are addressing a Save The Date or Invitation to a couple who is living together, but not married, whose name do you write first? Do you base it on alphabetical order, does the woman's name always go first, or do you write the name of the person you've known longer first? Sorry for such a dumb question, but I'm clueless!