Jessica Simpson Reveals She Wrote 'Love Letters' To Johnny Knoxville While She Was Married To Nick Lachey

Jessica Simpson has admitted that she strayed during her marriage to Nick Lachey, but not in the way many people may think. In her new memoir, the Open Book author revealed that she had an "emotional" connection with actor Johnny Knoxville near the end of her marriage to her first husband.

In a scathing excerpt from Jessica's book obtained by Radar Online, the former Newlyweds star admitted that she became emotionally involved with Knoxville while filming the Dukes of Hazzard movie with him in 2005.

Jessica was near the end of her marriage to Lachey at the time, while Knoxville was married to Melanie Cates. In her book, the mom-of-three admitted things began to get flirty with Knoxville as they filmed the action movie on location in Louisiana nearly 15 years ago.

"It was like Johnny and I were prison pen-pals, two people who wanted so much to be with each other but were kept apart," Simpson wrote, in reference to their spouses.

The actress, who played Daisy Duke opposite Knoxville's Luke Duke in the hit film, revealed that as her marriage to Lachey was crumbling, she and her co-star Knoxville started sending "love letters" to one another. Their emotional bond proved to be stronger than a sexual one.

"It's funny, I know, because I placed such an emphasis on sex by not having it before marriage," Jessica wrote in Open Book. "After I actually had sex, I understood that the emotional part was what mattered. And Johnny and I had that, which seemed far more of a betrayal to my marriage than sex."

Johnny Knoxville and Jessica Simpson arrive at the UK Premiere of new film
Getty Images | MJ Kim

At the time they were filming the Dukes of Hazzard film, tabloid rumors swirled that Jessica and Johnny were having an affair. In a 2005 interview with The Chicago Tribune, Jessica brushed off the rumors, noting that she would be more nervous if "people weren't interested." She also said she took the gossip as a "compliment."

Knoxville was less okay with it. The actor, who had a 9-year-old daughter at the time, said the rumors were "hard on the family."

"Luckily, my wife and I have a dialogue, and she understands -- but of course, she doesn't like it," he said.

During a 2006 interview on The Howard Stern Show, Knoxville was put to the test regarding the rumors. Polygraph expert Ed Torian asked Knoxville a series of questions to determine if he had an affair with his gorgeous co-star, and when he was asked "Did you have sex with Jessica Simpson?" the actor said no. The result came back as truthful.

In Open Book, Jessica maintains the relationship with Knoxville was never physical. One year after The Dukes of Hazzard was released, the blonde beauty divorced Lachey. Knoxville divorced his wife Melanie in 2008, and two years later he married Naomi Nelson.