The lifeblood of this movie is in throwing the amazing cast into awkward situations and watching them interact. The plot stays mired in "we need to tell my father we're married".
Peter's father is played by Charles Coburn who is so familiar to me that it surprises me that I can't find a single role of his in IMDB that stands out in my mind. Peter's mother is played by Beulah Bondi who was Ma Bailey in It's a Wonderful Life. Other familiar faces: Grady Sutton, Franklin Pangborn, Hattie McDaniel, Willie Best.
The only dancing that Ginger Rogers does is to teach Ma Bailey the Big Apple. This is the most commonly mentioned dance in MCMXXXVIII movies. I should try to go back and tag every movie where it occurs.
Peter and Francey are accidentally booked into an already occupied drawing room on the train back to Old Sharon