Sometimes when a writer is looking to stir things up, or prevent the inevitable progression of a relationship, or stop a wedding, we'll find out that oops, once upon a time our hero/ine had an Accidental Marriage, Arranged Marriage or Citizenship Marriage, possibly brought on by an Off the Wagon night. Which they then proceeded to forget about for years on end until their long-lost spouse comes looking for them wanting a divorce, or they want to marry their current SO. Occasionally they'll think the marriage was annulled or never really counted, or they'll foolishly trust their spouse to take care of doing away with the ill-advised nuptials. It can be a bit more forgivable if the returning spouse supposedly died.