Sex keeps me young and happy : Cameron Diaz...! Charlie's Angels star Cameron Diaz has revealed that sex is one of the reason of her youthful looks and is happy the way she looks. "I guess it's exercise, healthy diet, lots of water, lots of laughter, lots of sex. Yes sex, we need that as human beings. It's healthy, it's natural, it's what we are here to do," contactmusic.com quoted Diaz as saying. Diaz, 37, also said she has so far resisted the temptation to go under the knife to maintain her good looks. "I'm not doing anything right now," Diaz told. "So far, so good. But I'll never say never to anything. You've got to be realistic. I don't want to look 25 again." Diaz has been romantically linked to New York Yankees star Alex Rodriguez since February. Diaz also said she loves to make fun of herself to make people comfortable in her presence. "I love to make people laugh," she said. &q