Maddie and Ben have been dating for nine years and they know each other inside and out. Maddies younger sister, Mia, has been dating Casey for seven weeks. With a shared cest la vie attitude, Mia and Casey announce theyre getting married and having a baby. Its news that throws Maddie for a loop. Surprisingly, the girls parents, who have recently adopted a carpe diem sort of philosophy, couldnt be more pleased.