A 20-year marriage is impressive for any couple, but for a couple in Hollywood, it's pretty much unheard of! When actress Catherine Zeta Jones, 51, and Michael Douglas, 76, open up about their secret to a long and happy marriage, it seems like it would probably be pertinent advice to listen, because if anyone can last that long without planning a way for their spouse to mysteriously disappear, then they probably know what they're doing!