Actress and internet pin-up CINDY MARGOLIS has made her naked debut in men's magazine Playboy for the first time - 22 years after magazine boss Hugh Hefner first approached her to bare all. The sexy blonde opted to give in to Hefner's plea to celebrate her 40th birthday and raise cash for US national infertility association Resolve. Margolis says, "I was 18 when Playboy approached me for the first time. Every other year since then I would get a wonderful call from them, and I would very graciously decline. "When they called on my 40th, not only to wish me a happy birthday but also to make the offer again, I thought, 'Wow, they still want me.' "If I had done it in the past, it would have been for gratuitous reasons or money or to help my career. And I don't need any of that now." Instead, the sexy star has struck a deal with Hefner - a portion of the sales from the upcoming Christmas (06) issue of the magazine will go to Resolve. Margolis has become a poster girl for infertility treatments and the spokeswoman for Resolve after conceiving three children via in vitro fertilisation. She tells Playboy she's planning to write a book about her struggles to become a mother.