Yoon Doo Joon reveals that he had actually pretended to be sleeping while Jang Hyuk was talking!  Doo Joon commented, "While we were filming Iris 2, Jang Hyuk gave me a lot of advice on acting. Our friendship had gotten deeper when we started going to the same gym together." He then revealed that unlike Jang Hyuk's appearance, that the actor loves to talk. Doo Joon said, "When Jang Hyuk starts talking, he goes on for about 2 to 3 hours. Once, I pretended to sleep when he was talking during our flight." However, Doo Joon also added that Jang Hyuk is talkative but is very personable. (Source: Nate)