The teenage girl who came between Christie Brinkley and her estranged husband, Peter Cook, is talking about about their steamy relationship and how it became sexual.

Diana Bianchi, now 19, told WNYW, the FOX affiliate in New York, that she met the 47-year-old Cook in May 2005 when Bianchi, then 17, was working at a toy store in the Hamptons. Bianchi says Cook offered her a job at his architecture firm. Within a month, she says, things turned sexual.

“He’d make advances verbally towards me first,” Bianchi told WNYW’s Rosanna Scotto. “It just escalated into something I didn’t expect … I never expected that he would take it to a different level.”

Bianchi knew that Cook was married, but says that Cook never made her any promises. “He didn’t say he was going to leave her. He just basically left it at he wished things were different. He wished that he was younger or he had met me at a different time … I never asked him to leave her for me.”

At one point during the interview, Bianchi’s attorney stepped in, saying that Cook “preyed on her vulnerability, her naïveté, her age, her immaturity.”

Bianchi says Cook would leave money for her, even providing a down payment on her car.

Brinkley and Cook have been married for a decade. Bianchi could be a key witness in the couple’s divorce case, with a reported $60 million on the line. Bianchi’s lawyer, Joe Tacopina, says his client has “got a great sexual harassment claim” against Cook.

In all of this mess the kids will be forgotten. It’s all about money now.

Last week, Hollywood Grind reported that former supermodel Christie Brinkley was splitting from her husband of nearly 10 years, architect Peter Cook. Now, several news sources are reporting that the couple’s breakup may be the result of Cook taking an alleged interest in his 19-year-old assistant, Diana Bianchi. According to published reports, Cook allegedly provided Bianchi with a new car, large sums of money and promises to help her with a singing career.

Bianchi’s lawyer, Joseph Tacopina, is reported as saying that the young woman may sue Cook since she has grounds for sexual harassment.

Meanwhile, Brinkley, who reportedly found out about the alleged relationship from Bianchi’s stepfather, has packed up the couple’s two children and moved them out of town. Her publicist, Elliot Mintz says: “For me to say that she’s not hurt or shocked, that would just be foolish. I can’t characterize the degree of pain, but any woman reading this gets it.”

It was Mintz who confirmed the news of the split last Tuesday: “Yes, it’s true. The couple has separated. Christie’s primary interest at this difficult time is for the protection of her children and she would be most appreciative if people would be good enough to respect her privacy.”

The 52-year-old Brinkley, who played the comely blonde in the ’80s comedy ’National Lampoon’s Vacation’ with Chevy Chase, has been married three other times, most notably to “Piano Man” Billy Joel, who penned his hit “Uptown Girl” song for her.