Kevin Federline's memoir has a startling message for Britney Spears fans.

Kevin Federline is opening up about his tumultuous relationship with Britney Spears in a new memoir.

In excerpts obtained by The New York Times, the 47-year-old dancer and DJ makes some alarming claims about his ex-wife's behaviour and mental state in his upcoming book You Thought You Knew.

The revelations paint a deeply concerning picture of the pop icon's life post-conservatorship.

And frankly, they're quite difficult to read.

Watch the trailer for Britney Vs Spears. Article continues after video.

For those who need a refresher, Federline and Spears were married for three years before finalising their divorce in 2007. What followed was a messy, prolonged custody battle that ended in 2008, with Federline ultimately gaining custody of their two sons, Sean Preston, now 20, and Jayden James, 19.

The pair haven't spoken in years, according to Federline, but he's been watching from the sidelines as concerns about Spears' wellbeing have mounted. 

Now, he's decided to tell his side of the events. Here are the most shocking revelations from his memoir so far:

The Free Britney Movement was harmful.

Perhaps one of the most controversial claims in Federline's memoir is his assertion that the #FreeBritney movement — which successfully campaigned to end Spears' conservatorship — may have done more harm than good.

Following a very public mental health crisis in 2007-2008, Spears was placed under a conservatorship that controlled her finances and personal decisions for 13 years. In 2021, a Los Angeles judge terminated Spears' conservatorship after finding that it was "no longer required."

Image: Getty

But in his book, Federline argues that whilst the movement "started from a good place," it vilified people around Spears so intensely that professionals who could help her are now too afraid to step in.

"All those people who put so much effort into that should now put the same energy into the 'Save Britney' movement," he writes. "Because this is no longer about freedom. It's about survival."

The knife incident. 

The most disturbing allegation in the book involves their teenage sons and a knife. Federline claims that when the boys would stay at their mother's house, they lived in fear.

"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," Federline writes. "Then she'd turn around and pad off without explanation."

These shocking claims come at a particularly sensitive time for the family, as Britney has been allegedly working hard to rebuild her relationship with her two kids, following years of estrangement.

The pop star has been candid about the pain of their estrangement, sharing in an August Instagram post: "The hardest years of my life were my two sons gone for those 3 years. I was cut off from calling or texting… my secret to survival was denial and a lot of tears."

Image: Getty

However, since then, there have been signs of healing. After the boys moved to Hawaii with Federline in August 2023, Jayden reportedly reached out to his mum in late 2024 after years of barely speaking. 

Sources close to the family told Us WeeklySpears and her sons are now "healing together," with one insider claiming: "The boys are maturing and they want their mum in their lives, and Britney is really happy about that. She's so grateful to have them in her life. She feels whole again."

Recalling the night Britney was held involuntarily.

Image: Getty

Federline also opens up about the traumatic night in 2008 when Spears was taken to Cedars-Sinai Medical Center and placed under a 72-hour involuntary psychiatric hold following a three-hour standoff involving their children.

"It was one of the hardest nights of my life," Federline writes. "I felt sick over what she was going through. This was someone I had loved. Someone I had built a life with. The mother of my children."

The situation is "racing toward something irreversible". 

The most concerning part of Federline's memoir comes in the penultimate chapter, where he expresses his deepest fears about Spears' current state.

"The truth is, this situation with Britney feels like it's racing toward something irreversible," he writes.

Image: Getty

"It's become impossible to pretend everything's OK. From where I sit, the clock is ticking, and we're getting close to the 11th hour. Something bad is going to happen if things don't change, and my biggest fear is that our sons will be left holding the pieces."

Federline ends his book with a plea to anyone "who has ever been moved by Britney" to stand by his children and their mother. 

"Now, more than ever, they need your support," he writes. "I've been their buffer for years, but now it's bigger than me. It's time to sound the alarm."

Feature Image: Getty.