While rumors swirl of Ryan Seacrest dating Sports Illustrated model Dominique Piek, his ex, Julianne Hough, seems unfazed. The blond “Rock of Ages” star was spotted challenging her crew of girlfriends, including actress Jessica Szohr, to a game of life-size “Jenga” while snacking on boozy snow cones at a pool party in Beverly Hills for Svedka’s new flavors the other day. We’re told Hough’s brother Derek was also at the bash, surprising partygoers by leading a flash mob of dancers.