Cappy married Eveline Van Nieuwenhuizen, daughter of Willem Karel Van Nieuwenhuizen and Jeannette Antoinette Westerkamp, in Jember, Jawa Timur, Indonesia.
he marriage ended in divorce. (Eveline Van Nieuwenhuizen was born on 27 Feb 1917 in Bogor, Jawa Barat, Indonesia, died on 15 Aug 1994 in Almere Stad, Netherlands and was buried on 19 Aug 1994 in Jakarta, Indonesia.)