Liam Hemsworth popped up on the Paranoia set in Philadelphia with his costar Amber Heard yesterday. They filmed a car scene together before Liam got in front of the cameras solo. While Liam was working, his fiancée, Miley Cyrus, hung out nearby with her pal. She and buddy Cheyne Thomas were spotted driving around Philly and stopping at a coffee shop. Miley also has her dog Happy to keep her company and shared a cute picture of herself with the pup this morning. Miley's short blond hair was on display after Liam revealed that he thinks "it looks really fantastic." The duo are spending time in Pennsylvania while Liam's on location, but he'll soon switch gears to production on Catching Fire.