(CBS) For many women, Holly Hill might be the last woman on Earth they would take relationship advice from.
The beautiful 40-something Australian with a psychology degree spent a full year of her life as a well paid mistress, seeking out married men eager for sex and romance they weren't getting at home.
Now she has penned a book, "Sugarbabe" to offer insights she learned.
And the biggest one might shock: let your partner cheat, she says, as long as you negotiate the rules.
"One of the main things that I have learned is that a woman that negotiates infidelity with her partner is far more powerful than a woman who is sitting home wondering why he's late from the office Christmas party," she recently told CNN.
Hill believes that men - and some women - are designed to cheat.
"We just have to be honest about the way nature created us, and we have to work with nature instead of working against her. This isn't rocket science. This is what every man already knows and I think what every woman deep down already knows," she told the network.
The trick of the game, she says, is laying down the rules and following them; and keeping honesty front and center.
In her own relationship - she is no longer a mistress - she allows her boyfriend of two years to bed whomever he wants as long as he doesn't sleep over, take romantic weekends or spoon his partner.
He "can have sex with the Australian women's basketball team for all I care, but he can't spoon any of them," Hill told CNN. "For me, spooning is cheating."
How did Hill come to this?
The author says several years ago she was at a crossroads; her wealthy but married boyfriend had convinced her to quit her job and live off of his largess. Then he dumped her.
A friend urged her to be "open-minded" about her next career move. So she penned this classified ad and put it online.
"Attractive, professional, well-spoken, well-dressed 35-year-old woman seeks sugar daddy. I live in Darlinghurst on a 17th floor unit with fantastic skyline views to the harbor. The unit also features very discreet and secure undercover guest parking. I am looking for exclusivity so will (theoretically) be available to you 24 x 7. I am single and don't have any children. I am also a fabulous cook and can provide gourmet meals should you require them. I am a qualified psychologist so I make an excellent listener, and I have a great love of conversation. I have also worked for many years in public relations so am a clever, charming companion in just about any situation. I love sex. I will require a generous weekly allowance in return for all of the above."
She got 11,000 responses, according to CNN. And charged her clients $1,000 a week for her company. She says she didn't consider herself a prostitute and, in the end, only took five customers. Apparently, just enough, to write a self-help book.