I am looking for the identity of a black and white movie where the main characters at the end of the film are on their honeymoon and they say something about having all of the time in the world and then they move to reveal a lifesaver attached to the balcony that says Titanic (or Lusitania, some famous sunken ship).  The actor looked like William Powell and she was wearing one of those silk nightgown dresses I believe.  I literally do not remember anything else that happened in the movie, just being supremely upset when it suddenly ended.