What does Kevin Federline’s upcoming book say about Britney Spears?

Pop star Britney Spears’ ex-husband reveals new details about the pair’s strained relationship in his new memoir, You Think You Know.

Kevin Federline, her onetime backup dancer, offers a picture of Spears’ allegedly erratic behavior as a wife and mother and says he remains concerned about Spears’ health.

Spears spoke out against the book, which will be published Tuesday, and accused Federline of trying to profit from his relationship with her.

Federline makes a number of allegations against Spears in the memoir, which was shared with the BBC before the book’s publisher Listenin published it.

It accuses Spears of unhealthy behavior as a mother, including drinking while pregnant and taking cocaine while she was still breastfeeding her two sons. Spears has previously denied having a substance abuse problem.

Federline also claims that the couple’s sons were afraid of Spears when they were young. “Sometimes at night they would wake up to find him standing quietly in the doorway, watching them sleep – ‘Oh, are you awake?’ – with a knife in his hand,” he writes. “Then he would turn around and walk away without any explanation.”

Federline also expressed concerns about his estranged ex-wife, saying, “The truth is, this situation with Britney feels like it’s hurtling toward something irreversible. From where I sit, the clock is ticking and we’re approaching the 11th hour.”

He writes that Spears supports a conservatorship in which many aspects of her life have been controlled by others for years. Federline writes that the Free Britney movement “will never be able to fully get behind it.”

The two met in the summer of 2004, following Spears’ commercial peak.

They married a few months later and immediately welcomed two sons: Preston (now 20) and Jayden (now 19).

Spears filed for divorce in 2006 and the divorce was finalized in 2007.

The couple fought publicly over custody of their son, and Federline was eventually awarded custody of the children.

After Federline received full custody, Spears was seen behaving in a way that Federline described in her book as erratic.

He made headlines for things like shaving his head and hitting a photographer’s car with an umbrella.

These public incidents sparked concerns about his mental health, and after he was hospitalized twice, a temporary conservatorship was established in 2008 and made permanent the same year.

Spears continued this controversial arrangement until 2021, in which her father and others controlled her finances and some aspects of her personal life. She was unable to regain custody of her children until it was removed.

Spears accused Federline of attacking her at her recent press conference to promote her book. He described the contents of the memorial as “extremely hurtful and exhausting” but suggested that the work would sell better than his own memoir.

In the book The Woman Within Me, Spears accused her ex-husband of “trying to convince everyone that I was completely out of control.”

Spears also defended her relationship with her sons. “I have always begged and screamed to have a life with my boys,” she wrote on social media on Oct. 15, adding that “relationships with teenage boys are complicated.”

In a statement to US media, a Spears spokesperson added: “With the news of Kevin’s book boom, she and others are once again profiting from it and unfortunately this comes after the alimony with Kevin ended. All she cares about is her children, Sean Preston and Jayden James, and their well-being during this sensation. She detailed her journey in her memoir.”

The BBC has contacted Federline’s lawyer for comment on Spears’ counter-accusations.

Although the duo made headlines during their relationship and subsequent divorce, Federline in particular has largely stayed out of the spotlight in recent years. And much of Spears’s spotlight lately has been her social media posts.

Federline said he had been thinking about writing a book for many years, but wanted to wait until his children were older to complete it.

“Over a period of probably five years I picked it up and put it down quite a bit,” he told the Associated Press. “I think that describes me very well, who I am, the kind of father I am, the kind of husband I am, my ex-husband.”

He also told the AP: “I want my children to be able to move forward in their lives and know that the real truth of everything is out there.”