The Duke and Duchess of Sussex are celebrating eight years of marriage on May 19.Prince Harry and Meghan Markle on their May 19, 2018 wedding day.Credit: GettyThe GistOn May 19, Prince Harry and Meghan Markle will celebrate eight years of marriage.The Duke and Duchess of Sussex married in front of 1.9 billion people watching globally back in 2018.The couple’s favorite moment—which has to do with a certain music selection—is one they will “treasu…