Britney Spears dismissed rumors that ex-husband Kevin Federline is keeping their two boys from joining her 2-month Circus tour, her blog says. In fact, Sean Preston, age 3, and Jayden James, 2, will be with her at every stop, People notes, beginning March 3. The pop star promises a three-ring spectacle, incorporating elaborate performances with contortionists and fire. (More Britney Spears stories.)