Britney Spears is firing back after ex-husband Kevin Federline made explosive claims about her behavior during their sons’ childhood — including a disturbing allegation that she would stand silently outside their rooms at night holding a knife.

According to The New York Times, Federline makes the shocking accusation in his upcoming memoir, You Thought You Knew. “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,” the former backup dancer wrote. “Then she’d turn around and pad off without explanation.”

Federline, 47, alleges that the incidents made their sons, Sean Preston, 20, and Jayden James, 19, afraid to stay at Britney’s home following their 2007 split.

In response, a rep for Britney strongly denied the claims, telling Us Weekly, “With news from Kevin’s book breaking, once again he and others are profiting off her, and sadly it comes after child support has ended with Kevin. All she cares about are her kids, Sean Preston and Jayden James, and their well-being during this sensationalism.”

Britney’s team has not issued further comment to In Touch, who reached out following the bombshell excerpts.

Federline’s memoir also recounts the tumultuous period in early 2007, when Britney famously refused to hand over their sons during a custody dispute. That incident led to her being placed on an involuntary psychiatric hold at a hospital. “It was one of the hardest nights of my life,” he wrote. “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.”

Weeks later, Britney was placed on a second psychiatric hold, which triggered the start of her 13-year conservatorship and led to Federline being granted primary custody of their children.

Federline, who says he hasn’t spoken to Britney in “years,” also expressed doubts about the termination of her conservatorship in 2021. “It’s become impossible to pretend everything’s OK,” he wrote. “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.”

He even called on the #FreeBritney supporters to change their tune. “I urge all the people who fought so hard for the ‘Free Britney’ movement to now put the same energy into the ‘Save Britney’ movement. Because this is no longer about freedom. It’s about survival.”

Despite their strained relationship, Britney has shared heartfelt glimpses of her love for her sons on social media. Earlier this year, she reposted a video of one of her sons playing piano, writing, “Reposting because it’s a far better edit and excuse me crying and breathing hard !!! I was excited !!! Mamas don’t get enough credit at all these days !!! I mean just saying !!! I made a person !!! A live breathing person and I made two of them !!! And my boys are so incredibly sweet and charming !!! I’m so blessed.”