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.

As Gossip Girl fans first watched Upper East Side queen bee Serena van der Woodsen fall for resident lonely boy Dan Humphrey, Blake Lively and Penn Badgley were also feeling the sparks when the cameras weren’t rolling.

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.