 In an effort to get their families to join in the celebration of their upcoming wedding, Bobby and Liz convince their folks that the other s family is throwing an engagement party. Instead of working together, the families get competitive and try to outdo each other - which causes Liz and Bobby to flee to Vermont in frustration. Afraid that the young couple has eloped, the parents embark on a road trip to stop them - but a road trip with Mace and Philip is anything but a smooth ride.