THE ENQUIRER exclusively reports the shocking secrets behind Peter Cook’s Lolita mistress!

Diana Bianchi, the sultry teenager seduced by Christie Brinkley‘s cheating husband, is hiding some sizzling secrets, a close pal revealed.

The pretty brunette carried on a red-hot affair with Sean "Diddy" Combs, has undergone treatment for sex addiction, filmed a sex tape with a boyfriend and considered killing herself over her illicit romance with Christie’s hubby Peter Cook, her friend revealed to The ENQUIRER.

"Diana was taken advantage of by Peter Cook, but her behavior since the scandal broke has been out of control," the source, who passed a polygraph test, told The ENQUIRER.

Cook, now 49, first spotted Diana when she was just 17 and working as a toy store clerk.

He soon hired her as an assistant at his architecture firm. 

After Diana blossomed into 18, they launched a year-long affair.  

Diana’s stepfather alerted Christie to the affair in 2006 and the "Uptown Girl" threw out her philandering husband.

And while Cook reportedly paid Diana $300,000 not to slap him with a sexual harassment suit, her lawyers said she will testify in the case if called.

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