She has been a regular on men’s magazine Playboy but blonde beauty Pamela Anderson says she cried and felt sick when she posed nude for the magazine first time.Anderson was stunned when the adult publication asked her to bare all for them, the Contactmusic reported. “I was so confused. I told my mom about the offer and she said, ‘Do it. I’d do it’. I was so shy I was sick. They got the cover in the first roll of film because I was in tears… And then, after a while shooting, I became so comfortable they had to stop before I walked out of the studio door nude,” Anderson said.The 43-year-old Hollywood star first appeared as Playboy cover girl in 1989 and was selected as their Playmate of the Month in 1990.Since then Anderson has appeared for a record 13th time on the magazine’s 57-year publishing history, most recently for their January issue.The former ‘Baywatch’ star also regret going under the knife to enhance her appearance and has vowed to age gracefully