Knowles cheers on hubby Jay-Z at his London concert. Plus: Zac Efron, Heidi Klum, Gwen Stefani and more

GOOD CATCH

Rihanna has a hard time letting go of her boyfriend, L.A. Dodgers outfielder Matt Kemp, Friday in Los Angeles. The cute couple pucker up before he boards a flight to Arizona for a game against the Diamondbacks.