AceShowbiz - Simon Cowell's fiancee is set to tell all about the music mogul and their romance in a new autobiography, according to a U.K. report. Mezhgan Hussainy is putting pen to paper to write her life story, which will detail her childhood in Afghanistan as well as her family's escape from the country.

The 36 year old will also tell of her experiences as a make-up artist on "American Idol", where she met future husband Cowell. And reports suggest Hussainy is prepared to divulge plenty of personal information about the notoriously private businessman.

"And Simon is such a big part of her life that he will definitely get a mention. Simon is very private when it comes to his personal life so he might be hovering over the laptop when Mezhgan writes her final chapters."

The couple became engaged after record producer Cowell proposed earlier this year.