Article continues below advertisementIn a stunning twist that fans couldn't have seen coming, a simmering feud has erupted among pop royalty following the announcement of Kevin Federline's upcoming memoir, You Thought You Knew. As the world gears up for the book's release on October 21, the drama escalated when Nicki Minaj stepped into the fray to defend pop icon Britney Spears against her ex-husband's explosive allegations.