DEAR MISS MANNERS: How should formal letters be addressed to married gay couples?
GENTLE READER: Using two lines to address two people is such a simple solution that Miss Manners is surprised at the frequency of this question, whether in regard to opposite-sex couples with different surnames or professional titles, or same-sex couples.
However, when the latter share a surname, you may save a line by addressing them as The Messrs. (or Mmes.) Casey and Kelly Oglevy.