One of my all time favourites is the spanking scene in a Czech movie from the 80-s called Postriziny or Cutting it short. It's a funny movie, but unfortunately not recognised as such. Based on a short story by Bohumil Hrabal it's about a dull brewery owner married to a very vivacious woman, who is prone to all kinds of mischief. The spanking scene you can find at
http://disciplinedomestique.online.fr/medias-cinema.php