Fernando claims he has the inside scoop on Britney's orgies, threesomes and girl-on-girl kisses.
He reckons he's setting up a million-dollar deal with a major publisher. For maximum exposure, the book is being lined up to be released at the same time as Britney's wedding with Jason Trawick.
[See also: Britney Spears gets engaged to Jason Trawick]
The Sun reports Fernando told a friend: "Britney has a huge sexual appetite and, from what she told me, her tours were an anything-goes environment. I heard stories of threesomes, orgies, girls making out — things that would make your hair stand on end.
"She had a lot of young, attractive dancers around her on tour, and things would get crazy. There was drinking, drugs, steamy sessions in hot tubs, all sorts of things."
He added: "I was in her bathroom and saw this picture of her in a tub with some girls. It was very sexual. She told me, 'That was on tour and s*** got crazy'. I asked what she meant and she said they all got it on. Her and the girls."
This is the same former bodyguard who accused Britney of having "obnoxious personal habits" in court papers back in July. Hmmm.
Fernando worked for Britney in 2010 and launched a sexual harassment lawsuit against the singer, which is due to be heard this year.
Britney's team denied his allegations then, and her spokesman has denied Fernando's latest claims.
[See also: Britney Spears lapdanced for Joe Jonas on tour]