Sebastian Stan and Leighton Meester of Gossip Girl

Character names: Carter Baizen & Blair Waldorf
Years dated in real life: 2

Between 2008 and 2010, Leighton Meester dated Sebastian Stan, who played Carter Baizen, one of her character's many suitors on the CW series. But as characters on Gossip Girl change romantic partners like most people change socks, the on-screen relationship didn't last long. Carter, Chuck Bass' nemesis, was only a recurring character during the drama's first three seasons.