Kevin Federline has claimed that a phone call with a drunken Britney Spears was the "last straw" in their marriage.
In his new memoir, You Thought You Knew, the pop star's ex-husband alleges that she prioritised partying over taking care of their sons Sean Preston and Jayden James, now aged 19 and 20.
Sharing the moment when he realised enough was enough, Kevin recalled his alleged phone call with Britney and her friends Paris Hilton and Lindsay Lohan.
"I was in Miami for work, trying to stay focused on my commitments, and I got a call. It was her, Paris Hilton, and Lindsay Lohan on the line, drunk as hell, begging me to come over," he writes, reports TMZ. "I could hear Preston and Jayden crying in the background. It had to be three or four in the morning. That call was the final straw."
The former backup dancer, who was married to the Toxic singer from 2004 to 2007, claimed that it wasn't the first time that had allegedly happened, but that instance stuck with him the most.
"I'd already seen the photos in the tabloids, the ones of her out with them all night, partying at Paris's Malibu place," he continues. "But hearing my kids crying while she was doing God-knows-what? That was it. Any deep-seated sliver of hope that I'd held onto, that we might still somehow pull it together for the kids, died right then."
Britney has yet to respond to the latest allegation. However, her representative previously accused Kevin of "profiting off" the star, now that he no longer receives child support.
The rep added, "All she cares about are her kids, Sean Preston and Jayden James, and their well-being during this sensationalism."
You Thought You Knew was released on Tuesday.