Penn Badgley has revealed how playing the role of Dan Humphrey in "Gossip Girl" affected his relationship with his co-star, Blake Lively.

Penn Badgley is opening up about the challenges of dating his "Gossip Girl" co-star Blake Lively while working on the hit series. Badgley, who played Dan Humphrey, dated Lively, who played Serena van der Woodsen, from 2007 to 2010, mirroring their characters' onscreen romance.

The two starred in the original Gossip Girl, playing on-again-off-again lovers Dan Humphrey and Serena van der Woodsen. Sometime after the show started in 2007, Penn and Blake struck up a real-life, off-screen romance that lasted until 2010.