Sophia Bush REACTS to Kissing Kim Raver in Her 'Grey's Anatomy' Debut (Exclusive)

Sophia Bush chats with ET's Denny Directo at the 'Wicked' premiere in Los Angeles. The actress who made her 'Grey's Anatomy' debut last week as Dr. Cass Beckman, a trauma surgeon at Seattle Presbyterian Hospital, reacts to her kissing scene with Kim Raver. She also gives an update on the 'One Tree Hill' reboot. 'Wicked' flies into theaters on Nov. 22