Peter Cook Tells Barbara Walters About Past Failings, New Love

In the first interview since his divorce from former supermodel Christie Brinkley, Peter Cook told Barbara Walters he wants to set the record straight. Cook said he wants the world to know that the trial may have left his reputation battered and bloodied, but that it was absolutely necessary.

"This was never about money," Cook told Walters. "This was about me having access to my children. That's it."

Cook and Brinkley battled it out in front of the world this summer, exposing all the sordid details of their nasty breakup in what was one of the ugliest divorce trials on record.

The couple's dirty laundry made headlines almost every day, with Cook characterized as a narcissistic cheater, and Brinkley as a woman scorned, intent on a vengeful public flogging.

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The trial came two years after Cook, 49, admitted to having an affair with Diana Bianchi, his then-18-year-old assistant, whom he pampered with gifts and money, including a $300,000 payoff to avoid a sexual harassment lawsuit.

Bianchi testified on Brinkley's behalf at the trial, and after several days of testimony, Brinkley and Cook settled the case. Brinkley won sole custody of their two children, 10-year-old daughter, Sailor, and 13-year-old son, Jack, whom Cook adopted when he and Brinkley married. Cook received $2.1 million and visitation rights, but says he never had a chance to tell his side of the story ? until now.

Cook said Brinkley sent him packing after she found out about the affair and his involvement in online pornographic activity. She immediately limited his access to the children, and he says the humiliating ordeal he endured was really about them.

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"I was fighting to continue the role in my children's lives that I had played in their entire lives," Cook said.

"The misinformation that came out during the trial is the elephant in the room for my kids and I'm hoping maybe I can correct some of the wrongs," he told Walters.

Brinkley's attorneys went to court Wednesday asking the judge for a restraining order to keep the children away from Cook until the end of this weekend. She wanted to shield the children from the press attention that would follow the broadcast of the "20/20" interview. The judge ruled that the children would stay with their father for the weekend for his court-appointed parenting time.

In a statement sent to ABC News Wednesday, Brinkley's lawyer, Robert Stephan Cohen, said on behalf of the supermodel: "It is a measure of Peter Cook's character that he has breached the confidentiality agreement that is in the divorce settlement and has sought to present this distorted one-sided view of his marriage. Mr. Cook had his days in court, testified on his own behalf and ultimately agreed with the view of the children's court appointed attorney and psychiatrist that the children should live principally with their mother and that she should be the sole custodial parent."

Fairy-Tale Relationship Gone Wrong

This was a far cry from the fairy-tale marriage that most people saw for 10 years.

Once the world's highest-paid supermodel, Brinkley had the longest running contract with a cosmetics company. But she wasn't just a Cover Girl, she was also an "Uptown Girl," a song written specifically for her by singer Billy Joel, whom she later married. She was touted as one of the world's most beautiful women, but seemed to be less successful in love.

After three failed marriages, it looked like in 1996 she had met Mr. Right. Cook was a handsome, charming Hamptons architect who designed multimillion-dollar estates for New York's rich and famous. The couple wed when Brinkley was 42, and outwardly at least, they were a happy, glamorous celebrity couple who by all accounts really loved each other.

But eventually, Cook says, things changed.

"At some point I realized my needs hadn't been taken care of, and I took the cowardice way out and had an affair instead of approaching my wife and saying, 'You know what? I'm not happy.'"

Although he's not sure exactly when their marriage broke down, Cook says he was seeking attention and acknowledgement for his contributions to the family.With Cook' s advice, Brinkley bought and resold 18 properties reportedly increasing the family's worth five times over, to between $60 and 80 million.

He says he restored many of the 18 properties Brinkley purchased while with him, which increased the family's wealth five times over to a reported $60 million to $80 million.

"I wanted a little thank you every now and then for the amount of time I took to care for her and my family, for the wealth I was building," Cook said.

Cook says despite what he was feeling, he understands Brinkley's anger.

"Christie is mad at me. She's entitled to be mad at me. I'm an idiot. I made a mistake," Cook said.

Cook's Affair: 'It Was About Sex'

Cook told Walters he met Bianchi when she was 17 years old and working at a toy store in Southampton, N.Y. She needed a better paying job and he needed an assistant.

"I needed this help done and if anyone's gonna do it," Cook said, "why not this cute, sparkling girl?"

Cook says he did not intend to have a relationship with her, but mutual attraction turned to flirting, which then turned into a consensual relationship.

"We weren't looking to build a life," said Cook. "It was about sex. It was something we both wanted."

Cook said he and Bianchi had sex nearly a dozen times, having trysts in his office and in various vacant homes that he and Brinkley owned. He said he strayed from his marriage because he was seeking a connection he wasn't getting at home.

"I just suddenly realized when I was getting attention from someone else, that this is something that is missing in my life," he said.

Cook says the affair had been over for months when, in 2006, he attended a speaking engagement with Brinkley where they were approached by Bianchi's stepfather, who demanded that Cook end the affair with his teenage daughter.

Brinkley was devastated and Cook says he knew at that moment that his marriage was over.

"I felt horrible," he said. "I felt horrible for what I'd just done to my family."

Marriage Dissolves: 'I Was Dead to Her'

In that moment the 10-year marriage evaporated. Cook says he left with one suitcase.

"There was never a chance to heal our family," Cook told Walters. "What I had done was wrong. From the day she found out, I was dead to her."

After he told Brinkley the details of the affair, Cook also told her about his interactive involvement in online porn, going so far as to give her his passwords to the lurid Web sites where he watched pornography and participated with strangers in online sex acts.

"I told her everything," he said.

The media reported during the trial that Cook had a $3,000-a-month online porn habit, but Cook says this is untrue.

"This was quite simply, one-on-one interactive pornography. This was not me broadcasting a show on a Web site, showing myself to the world," he said. "Never my face, never my name and if it happened -- excuse the pun -- a handful of times, that's it. I do not have a pornography habit. I ... it was coincidental with a very painful time in my life."

Cook says he has not logged onto any Internet pornography sites since the breakup.

Cook Advocates for Role in Children's Lives

Cook does not believe his failings as a husband translate into failing as a father. He says the trial wasn't about money, as he had signed a prenuptial agreement; it was only about the importance of his role in his children's lives and Brinkley's attempt to limit his access to them.

"They've got a mom who loves them and they've got a dad who loves them and I think that's the most important thing," Cook said.

Brinkley stated during a news conference that the trial could not be avoided. She said "a mother's greatest fear is someone trying to take away your children."

"Parenting is a partnership," Cook told Walters. "I carried the greater percentage of the burden of that partnership. I was more apt to be the one to be there, just because I am in my nature, a doer."

When asked about Brinkley's role in the day-to-day life of the children, Cook said she was "not as involved as ... as myself. Generally it was my role to wake up with the kids, to get them started for the school day."

"He just was an amazing dad," said Shauna Hunter, the family's former nanny. "They always wanted to be with him. He did everything for his children and really loved them. He was their everything."

The couple reached a settlement before Cook's lawyers presented his case. Brinkley has sole custody of the children, and Cook was given significant parenting time in the summer and visitation rights.

"The first opportunity I was given to have [the trial] stop, I took it," he said. Even though he emerged from the trial "bloodied," Cook said he was satisfied.

"Of course I would have liked more, but I'm very happy that I can play as meaningful a role in my children's lives as I do. I have my children 40 percent of the year," Cook said.

Moving On: 'I Am What I Am'

With the dark days of the trial behind him, Cook says life is looking a lot sunnier. He has found a new love in Suzanne Shaw, who is a single mother and whom he's introduced to his children.

"The trial is over and she's in our lives so they've become more comfortable with her and understand that she's not trying to take over for mom," Cook said. "They also know she had nothing to do with what happened."

Cook sees his future as all smiles.

"I have no choice but to be healthy, happy and prosperous because that's what best for my children."

These days Cook wears a bracelet with the poignant inscription, "I am what I am." Cook says he is a human being that makes mistakes, but above all he is a good father.

"I think it's critical for them to have their father in their lives, to know how much I love them," he said. "How I'll always be able to turn to my children and say, I did everything. ... I sacrificed my reputation. ... I did it because I wanted to see my children. I wanted to be in their lives."