Hm, I thought I had this worked out, but FI and I just got an invite to my cousin's wedding that was addressed as:
Mr. FI
Ms. Irishcurls
Address
But they have never met my FI, so it got me thinking....to our unmarried guests that we're including guests that we don't know well/never met, does the man always go first? Regardless of relationship to the B&G?