Jesse James: How I told Sandra Bullock I cheated on her

Actress Sandra Bullock and her husband Jesse James arrive at the 2010 Vanity Fair Oscar Party Hosted after the Oscars on March 7, 2010. Bullock won an award for best actress that night; James confessed he was cheating on her soon after. (Photo: Jordan Strauss/WireImage)Actress Sandra Bullock and her husband Jesse James arrive at the 2010 Vanity Fair Oscar …Last year, when Jesse James of the motorcycle dream shop (and former reality-TV show) West Coast Choppers, confessed that he'd had an affair, celebrity watchers wanted to know: "How could anyone cheat on a superstar like Sandra Bullock?"

And then: "How did he tell her about it?"

Now, he's sharing the humiliating moment in his new memoir, "American Outlaw."

"I admitted the affair," he writes. "I told her the hard details. I let her know that I had never loved this woman, that I had never cared for her at all."

James, 42, says Bullock's publicist called to warn him that "tattoo model" Michelle "Bombshell" McGee had talked to the tabloids about their relationship. He decided to come clean to his wife of almost six years, actress and all-American favorite Sandra Bullock, 46.

"The feeling of shame and sadness that washed over me as Sandy began to cry was almost beyond measure," he writes in his book. "I didn't touch her. I sat frozen in my chair, watching, as Sandy's small body shook with sobs."

"Sandy rose to her feet. She unfolded her sunglasses and put them on her face. She walked steadily and purposefully to the front of the shop, opened the heavy, metal door. For a moment, the sunlight enveloped her. The door closed behind her, and she was gone."

James also had to break the news to his children, Chandler, Jesse Jr., and Sunny. Sunny was especially close to her step mom, though James now says that Bullock hasn't had contact with the little girl for months. "Well, sweetie, the truth is, I have no idea," he says he told Sunny when she asked where Bullock was. "Daddy f**ked up, real, real bad, so your stepmommy decided to disappear for a few weeks."

During an appearance on "Good Morning America" today, James justified writing about the affair. "I can't worry about her anymore," he said. "It's time to make sure I'm happy." He and 29-year-old "L.A. Ink" star Kat von D are set to get married this summer. The two got engaged in January; theirs will be his fourth marriage.

Jesse James and Kat Von D attend L.A. Gay & Lesbian Center's 'An Evening With Women' at The Beverly Hilton hotel in California last month. (Photo: Jason LaVeris/Getty Images)Jesse James and Kat Von D attend L.A. Gay & Lesbian Center's 'An Evening With Women' at …"We like the same music, we like tattoos, we like art, everything," he told People magazine this week. "I believe 100 percent that she loves me and you know what? I've never believed that about anybody."

"She fell in love with me when I was being called Satan," he said. "If that's not a testament to what kind of a person she is and where her intentions are, I think nothing is."

As if to underscore the type of person he is, though, James went on Howard Stern's Sirius XM radio show today to say that Von D is "100 percent" better in bed than Bullock, the NY Daily News reported.

He also told the shock jock that he wasn't cheating on Bullock from the beginning of their relationship, but started "a couple of years" in because he never felt comfortable in her Hollywood world-and that he probably wanted to get caught. "I think subconsciously I did...but I didn't think it would be as crazy as it got," he told Stern.

Good luck with that, Kat.