Kevin Federline planning tell-all book on Britney's deep-dark secrets

Insiders believe that he is thinking of selling their sex-tape to the highest bidder, which they made shortly after they got married, besides raking in millions from his tell-all expose on Britney’s secrets.

"He's either hoping a publisher will pay him big bucks for the book or Britney will cough up more than what's in their prenuptial agreement to keep him from spilling the beans," said the source.

"I think he's willing to air their dirty laundry to get what he wants. He doesn't seem to care where his money comes from, as long as he gets it," he added.