Catherine Zeta-Jones and Michael Douglas are Hollywood icons, and their relationship is almost as famous as their films.The A-list couple, who are now neighbors with King Charles, have been together for over 20 years and share two children together. See the lovely Instagram story the Fatal Attraction star put together to celebrate his wife's birthday and their relationship in the video below.WATCH: Michael Douglas' celebratory photo reelThe Mask of Zorro star actually shares her September 25 birthday with Michael, and that's just one connection that brought the two together.