The cozy couple continue their joint birthday celebration in Sin City. Plus: Sienna Miller, K-Fed and more

FAN CLUB

Kevin Federline brings his rap to the streets of Washington, D.C., on Saturday, where he took time for an impromptu meet-and-greet with fans. Federline performed Sunday in Norfolk, Va., to promote his new album, Playing with Fire. So what's next for K-Fed? He's scheduled to return to his native California for three more concert dates this week.