Catherine Zeta-Jones and Michael Douglas share a birthday. The couple, which has been together for 21 years, added another set of photos to their yearly ritual, celebrated the special date together.Catherine Zeta-Jones and Michael Douglas chase waterfalls with their kids in DominicaThe Addams Family: First look at Catherine Zeta-Jones and Luis Guzmán as the ParentsA post shared by Catherine Zeta-Jones (@catherinezetajones)Both Douglas and Zeta-Jones shared photos of the date, which show them blowing out a candle on a beautiful three-tiered chocolate cake. Zeta-Jones’ post is made up of two photos of herself and her husband blowing out the birthday candle, which says 25, the date of their birthday.