Avery had the whole bachelorette party planned. Everyone was flying to Chicago for a weekend filled with booze, clubs, comedy shows, shopping, and a trip to the spa. She had decorations for the hotel room, bags full of snacks, a glitter sash for the bride, and an itinerary detailing every minute of their days. But when the other bridesmaids befriend a bachelor party while she's ordering drinks at the bar, the whole weekend, and Avery's entire summer, are completely derailed. Needless to say, Niall Horan was not part of the plan.