Rihanna is too scared to pose nude.The stunning 19-year-old singer is famous for her raunchy music videos, but says she won't be tempted to pose nude - regardless of the amount of money she was offered.She told FHM magazine: "I am only 19! My mother would kill me if I posed nude!"A source close to the singer added Rihanna's new boyfriend Josh Hartnett wouldn't be too happy about his Barbados-born girlfriend stripping off for an adult magazine.The source said: "Josh really wants to date someone sweet and innocent that he can take home to his parents. If Rihanna decided to pose nude, it would destroy the whole image she is building for herself as a singer and as a girlfriend."While Rihanna has vowed never to strip naked for a photoshoot, she is happy to be seen as a "sexy" star.She said: "Let's just say I want to do things my way. I can be stubborn. If someone wants to force me to do something, I'll end up doing the exact opposite.

"I have to be myself. If I want to be sexy, I mustn't restrict myself. I want to be young, fun and sexy."