“May I just say that on his explosive album and in all the press that surrounded it, Justin neglected to mention the several times he’d cheated on me?” Spears says in her new tell-all memoir, The Woman In Me.

In Britney Spears’ new tell-all memoir, The Woman In Me (out now), the pop star is finally setting the record straight on how Timberlake’s “Cry Me a River” music video veered from the truth of their infamous relationship. The 2002 hit song’s music video features a woman who looks eerily similar to Spears cheating on Timberlake, while he walks around heartbroken in the rain singing about her infidelity. Timberlake confirmed about a decade later that his breakup with Spears inspired the track, but now Spears is telling her side of the story — specifically that it was Timberlake who cheated on her multiple times and broke up with her via text, which sent her into a depressive state from which she didn’t heal for a long time.

“In the news media, I was described as a harlot who’d broken the heart of America’s golden boy,” Spears writes. “The truth: I was comatose in Louisiana, and he was happily running around Hollywood. May I just say that on his explosive album and in all the press that surrounded it, Justin neglected to mention the several times he’d cheated on me? There’s always more leeway in Hollywood for men than for women. And I see how men are encouraged to talk trash about women in order to become famous and powerful. But I was shattered.”

Justin Timberlake and Britney Spears at the 2000 MTV Music Video Awards. DAVE HOGAN/GETTY

Spears shares that she understood how “the thought of my betraying him gave the album more angst, gave it a purpose: s—-talking about an unfaithful woman … The only problem with the narrative was that, in our case, it wasn’t like that.”

Watching the world celebrate and feel “very sorry for” Timberlake while shaming her made their breakup even more difficult for her. “I felt there was no way at the time to tell my side of the story,” she says. “I couldn’t explain, because I knew no one would take my side once Justin had convinced the world of his version. I don’t think Justin realized the power he had in shaming me. I don’t think he understands to this day.”

After “Cry Me a River” came out, Spears remembers getting booed everywhere she went, including a Lakers game with her family where “the whole arena” booed her.

Earlier in the book, Spears claims that Timberlake had been unfaithful while they were together. “There were a couple times during our relationship when I knew Justin had cheated on me,” she says. “Especially because I was so infatuated and so in love, I let it go, even though the tabloids seemed determined to rub my face in it. When NSYNC went to London in 2000, photographers caught him with one of the girls from All Saints in a car. But I never said anything. At the time we’d only been together for a year.”

She also remembers how one of her dancers “who’d been hanging out with him” told her about Timberlake bragging about hooking up with another woman. “He’d gestured toward a girl and said, ‘Yeah, man, I hit that last night,'” Spears says the dancer told her. “I don’t want to say who he was talking about because she’s actually very popular and she’s married with kids now. I don’t want her to feel bad.”

Spears adds that her friend “was shocked and believed Justin was only saying it because he was high and felt like bragging. There were rumors about him with various dancers and groupies. I let it all go, but clearly, he’d slept around.”

She says that’s why she ultimately cheated on Timberlake one time as a result of his infidelity but told him the truth as soon as it happened. She admits that she made out “one time” with her choreographer Wade Robson during a night out when they went dancing together. “I was loyal to Justin for years, only had eyes for him with that once exception, which I admitted to him,” Spears says. “That night was chalked up to something that will happen when you’re as young as we were, and Justin and I moved past it and stayed together. I thought we were going to be together forever. I hoped we would be.”

After Timberlake broke up with her via text, Spears says she heard he was sleeping around. “Justin ended up sleeping with six or seven girls in the weeks after we officially broke up — or so I heard,” she says. “Hey, I get it, he was Justin Timberlake.”

In an early excerpt from her book that PEOPLE debuted exclusively last week, Spears revealed that she became pregnant with Timberlake’s baby but had an abortion because he wasn’t ready to become a father. The pregnancy “was a surprise, but for me, it wasn’t a tragedy,” Spears says. “I loved Justin so much. I always expected us to have a family together one day. This would just be much earlier than I’d anticipated … Justin definitely wasn’t happy about the pregnancy. He said we weren’t ready to have a baby in our lives, that we were way too young.”

Spears and Timberlake were in their late teens and early 20s when they dated from 1999 until 2002. “If it had been left up to me alone, I never would have done it,” Spears says of the procedure. “And yet Justin was so sure that he didn’t want to be a father.” She goes on to describe the at-home abortion experience as “one of the most agonizing things I have ever experienced in my life.”

Spears would go on to welcome sons Sean, 18, and Jayden, 17, with her ex-husband Kevin Federline. Timberlake, who married actress Jessica Biel in 2012, is father to sons Silas, 8, and Phineas, 2.