On Again, Off Again, Lohengrin

T1, E1: The bickering Hubbards and Buells are stunned when their kids return from a night out announcing they're engaged. After arguments about the wedding plans are finally settled (amid the kids breaking up over a fight about whose mother is right), the kids wind up eloping with another couple, while their parents are trying to rescue Kaye's beloved grand piano, set up in the Hubbards backyard for the next morning's nuptials, from a midnight rainstorm.