Page Six items

“ALL IN” PAGE SIX: Today’s music-centric column reveals that LMFAO’s Redfoo, a former player on the junior tennis circuit, has been hanging at the U.S. Open as Ayaka Okuno’s coach while also promoting his Party Rock line of tennis gear. A spy sitting near Brooklyn Decker during an Andy Roddick match over the weekend was overheard questioning, “Who would play tennis wearing that?”… Gym Class Heroes frontman Travie McCoy penned “All In” for the N.Y. Giants, which he’ll perform tonight at the season kickoff against the Dallas Cowboys. Other artists who wrote songs for teams as part of the Pepsi NFL anthems campaign include Kelly Clarkson (Cowboys), Kid Rock (Detroit Lions), Wiz Khalifa (Pittsburgh Steelers) and Ice Cube (Oakland Raiders)… And Girls creator Lena Dunham is dating Fun. guitarist Jack Antonoff, and the pair have collaborated on a video. (9/5a)