Blake Lively is Southampton Sexy

Blake Lively sports some sexy summer dresses for her character Serena van der Woodsen on the set of her hit CW drama, Gossip Girl, in Southampton, N.Y., on Thursday afternoon.

Later in the day, Blake was seen holding hands with her on-and-off-screen lover Penn Badgley (pictured below). These two are attached at the hip!

Their costar Chace Crawford was also spotted on set (see below). The season 2 premiere of Gossip Girl premieres on Monday, Sept. 1.

10+ pictures inside of Southampton sexy star Blake Lively…