LOS ANGELES -- LOS ANGELES (AP) -- Kevin Federline says concern for his two sons with Britney Spears long kept him from telling his story, and those same concerns are the reason he's telling it now that they're men.

In a memoir to be released Tuesday, "You Thought You Knew," Federline documents his difficult years as husband, ex-husband, and co-parent with Spears, who wrote her own memoir in 2023.

Federline's includes some salacious stories and some potentially disturbing details about her behavior that have already made headlines.

"I want my children to be able to move forward in their lives and know that the actual truth of everything is out there," Federline, 47, told The Associated Press in a Zoom interview, backed by palm trees in Hawaii, where he now lives with wife Victoria Prince and their two daughters. "That's a very, very big part of this for me. And it's really important that I share my story, so they don't have to."

He and Spears' son Preston is now 20 and his brother Jayden is 19. They have little relationship with their mother.

Federline was a 26-year-old backup dancer for other major pop acts when he coupled with Spears in 2004. Their courtship, two-year marriage and divorce took them through one of the most intense celebrity media frenzies in modern history. Federline was ruthlessly roasted as a loser hanger-on, especially after he released his own deeply mocked hip-hop album.

"I wasn't just famous -- I was infamous," he writes.

He told the AP he long considered writing the book, but recently got serious about it.

"I picked it up and put it down quite a lot over probably a five-year period," he said. "I think that it's a very good description of me, who I am, the father I've become, the husband I am, the ex-husband I am."

-- Federline describes the night he and Spears first connected at a Hollywood nightclub, and how they hooked up hours later in a hotel bungalow: "Britney turned around, slipped off her underwear and started kissing me, tearing at my clothes with both hands. We stumbled toward the bed while I struggled to kick my pants off my ankles. This. Is. Happening. OK, sorry. Calm down, that's as detailed as I'm going to get."

-- He writes that a "San Andreas-level seismic shift in my reality" followed a few hours later when he left the hotel with Spears and dozens of paparazzi cars followed them.

-- He describes the night before their wedding, when Spears called her ex Justin Timberlake, seeking closure: "She never really got over him. She might've loved me, but there was something there with Justin that she couldn't let go of."

-- Federline said seeing Spears drinking while pregnant "tripped the silent alarms in my head." He later was outraged when he saw her doing cocaine when the boys were still breastfeeding, saying "are you seriously going to go home after this and feed them like you don't have a body full of drugs?"

-- He writes that Preston told him Spears mercilessly mocked him and once punched him in the face.

-- He says the boys began refusing to visit her when they were 13 and 14, and later told him stories that "shook me to the core." "They would awaken sometimes at night to find her standing silently in the doorway, watching them sleep -- 'Oh, you're awake?' -- with a knife in her hand."

Spears responded with a statement on her social media accounts. She said Federline has engaged in "constant gaslighting."

"Trust me, those white lies in that book, they are going straight to the bank and I'm the only one who genuinely gets hurt here." She said, adding that "if you really know me, you won't pay attention to the tabloids of my mental health and drinking."

She also addressed her relationship with her sons:

"I have always pleaded and screamed to have a life with my boys. Relationships with teenage boys is complex. I have felt demoralized by this situation and have always asked and almost begged for them to be a part of my life. Sadly, they have always witnessed the lack of respect shown by (their) own father for me."

An attorney for Spears did not respond to a request for comment.

Federline writes about growing up in Fresno, California, and finding "my therapy and my purpose" through dance.

He reminisces about his first big tour, with Pink, and working with Aaliyah, Destiny's Child and Michael Jackson. He details wrestling with John Cena in the WWE and appearing in a self-mocking Super Bowl commercial.

Federline says Preston and Jayden are living on their own as young adults, and have both been working on making music that makes him proud.

He weighs in on Spears' dissolved court conservatorship, saying it was necessary but hurt most of the people involved. He said the fans who fought to free her left an unfortunate legacy.

"The Free Britney movement may have started from a good place, but it vilified everyone around her so intensely that now it's nearly impossible for anyone to step in," he writes.

He says in the book that he wrote it in part as a public plea for her to get more help.

"I've lost hope that things will ever fully turn around," he writes, "but I still hope that Britney can find peace."

Kevin Federline says his sons with Britney Spears are the reason for his new memoir