Federline, 47, recalled the January 2008 incident in his new memoir You Thought You Knew, writing that sons Sean Preston, now 20, and Jayden James, now 19, had spent the afternoon with Spears, 43, and were in the process of going back to his house when things went “sideways.”

Kevin Federline has taken another brutal swipe at Britney Spears' third husband, Sam Asghari, after the actor called him a "professional father."

Federline’s memoir claims include serious allegations about Spears’s behavior during their marriage and after.