Las Vegas knows how to party, and for once, event planner Liv McKay won't be entirely behind the scenes. The Dixie gang is in Sin City to celebrate Mama and Earl's rockin' Elvis-themed wedding. And between juggling the botched bachelorette party and a problem-plagued soir e back home, Liv's ready to double down on some fun. Mama & Earl's happily-ever-after seems like a sure thing, but all bets (and nuptials) are off when they get to the Burning...