Kevin Federline revealed his sons Sean Preston and Jayden James have read some of his upcoming memoir, which includes explosive claims about his ex-wife and their mother, Britney Spears. "Pieces of it, but, I mean, they know all of this stuff, right?" Federline, 47, told Us Weekly during an exclusive interview on Wednesday, October 15. "I've talked to them about many, many things over the course of their teenage years, so, in a nutshell, yes, they know everything that's in there.