Barbara Walters Exclusive: Peter Cook on Affair

In his first interview since his bitter public divorce from former supermodel Christie Brinkley this summer, Peter Cook told Barbara Walters that "I felt like I was a guest in someone else's life."

Many were shocked when Cook and Brinkley split, after 10 years of what from the outside looked like a perfect marriage. Their divorce proceedings this summer were some of the ugliest in recent memory.

Cook spoke to Walters about what went wrong, his affair with a teenager and the $300,000 payout to her, his reported $3,000-a-month Internet pornography addiction and why he was willing to have his dirtiest secrets revealed in the fight over access to their children after the divorce.

Watch the interview Friday on "20/20" at 10 p.m. ET

Peter CookPlay

Cook told Walters why he started an affair with the young woman in 2005, when he had a great marriage in 2004.

"I was seeking a connection I could not find in my own marriage," he said. "I think the emotional aspect of our lives had changed. I think we were both feeling more like we were living with a brother and sister than a life partner. … I think I just suddenly realized when I was getting attention from someone else that this is something that is missing in my life."

When asked what he wanted, Cook said, "I wanted a little acknowledgement, a little attention, a little thank you every now and then for my efforts, for the amount of time I took to care for her and my family, for the wealth I was building. Just the tremendous amount of work I was putting into my family. … My world became her world. It had to be that way. … There came a time when I pulled up [to] the driveway to the home that I found, that I built, that I lived in, and I felt like I was a guest in someone else's life."

Cook said that he agreed to be interviewed to try to "correct some of the wrongs."

"My hope is that the world will see that I'm not the scum bag pervert that I've been painted to be," he said. "The misinformation that came out during the trial is the elephant in the room. It's the elephant in the room for my kids. And I'm hoping maybe if I can correct some of the wrongs."

When asked whether he wanted his ex-wife to see the interview, Cook said, "I don't think I can avoid that. But I think if she does, what I hope comes of it is that she takes the time to heal herself. And she goes back and remembers that I made a mistake, but that I am that person that she wrote the poems about, that she raved about in magazine articles and anybody who she could get … twist their ear to listen. I am that person today, that I was then."

For much more of Walters' interview with Cook, watch "20/20" Friday at 10 p.m. ET