Britney Spears has admitted to having an affair with Justin Timberlake, whom she dated for three years in the early 2000s.

According to an exclusive report by Us Weekly, Spears wrote in her long-awaited memoir, The Woman in Me, that at one point while dating Timberlake, she danced and made out with choreographer Wade Robson in a Spanish bar.

In the book, Spears explained that she and the NSYNC alum "agreed to put the incident behind them."

There have been many rumors over the years about Spears' infidelity, sparked by Justin Timberlake's song "Cry Me a River" and its video. The lyrics include the words "You don't have to say / What you did / I already know / I found out from him." In the music video, the main character, played by Timberlake, is filmed breaking into the home of someone who appears to be Spears and having it out with another woman, presumably for revenge.

The "Toxic" singer addresses the controversial music video head-on in "Woman in Me," describing it, incredibly, as "a woman who looks like me cheating on me and he wanders sadly in the rain. I don't know the whole story, and I try to be as fair as possible to both sides, but I have to admit that this one little sentence is enough to get me hooked on just how accurate yet how scathing she is.

The singer also noted how the video had damaged her reputation and how disproportionate the backlash had been. Despite the fact that, in her own words, she was actually "in a coma in Louisiana and he was happily running around Hollywood."

In another part of her shocking memoir, Spears also accused Timberlake of cheating on her with another celebrity and revealed that Timberlake had an abortion during their relationship because she was not ready to have children.

"Woman in Me" was released on October 24.