My situation is very unique, and I have been scouring the internet for suggestions. My mother is deceased, but my father has not remarried. My FI's parents were never married. His mother is married, and his step-father is heavily involved in his life, but so is his father, who is single. We really would rather avoid "together with their families" because everyone in our families is really giving their all for this wedding!
So, is it inappropriate to do Mr. & Mrs., then another line for Mr. and Mrs., and then a Mr. for his dad? It looks wordy on the invitation, but it's the best way to make sure everyone is recognized. Is this proper and okay? What does everyone think?