Playboy magazine founder Hugh Hefner poses with his six girlfriends (L-R) Sheila Levell, Izabella St James, Zoe Gregory, Holly Madison, Bridget Marquardt and Cristal Camden, pose for the cameras. (September 20, 2003) (Reuters Photo)
Karissa Shannon and Kristina Shannon on a Playboy magazine cover.
Kimberley Conrad was chosen as Playboy's Playmate of the Month in January, 1988.
She gor married to Hugh Hefner in July 1989.
Conrad and Hefner parted ways after being together for nine years.
Barbi Benton featured on the Playboy magazine cover many times.
1926 born, Hugh Hefner is famous for his colourful personal life. Have a look at his sexiest girlfriends so far. (Reuters Photo)
Bridget Marquardt dated Hugh for a long time.
Brande Roderick dated Hugh in early 2000s.
Kendra Wilkinson is best known for her affair with Hefner.
Holly Madison and Hefner were together for many years.
Crystal Harris got engaged to Hugh Hefner in December 2010.
Kara Monaco was chosen as Playmate of the Month by Playboy magazine in June, 2005.
Kara Monaco with Hefner at a do. (Reuters Photo)
Harris broke off the engagement on June 14, 2011, five days before their planned wedding. (Reuters Photo)
Holly Madison wanted to marry him and have kids, but that was not Hefner's priority. (Reuters Photo)
Kendra Wilkinson is a glamour model and television personality now. (Reuters Photo)
Bridget Marquardt is an American television personality, model, and actress. (Reuters Photo)
It was a dream come true for Barbi Benton (L) when Hugh asked her to be his real life girlfriend. (Reuters Photo)
Playboy models and twin sisters Kristina and Karissa Shannon. (Reuters Photo)
Publisher, founder and chief creative officer of Playboy Enterprises, Hugh Hefner turns a year older on April 9.