Sebastian Stan Hints “Gossip Girl” Costar Leighton Meester Was His First 'Serious Love': 'Life Seemed Simpler'
Though he doesn't directly name his Gossip Girl costar and ex-girlfriend Leighton Meester, the two dated from 2008 to 2010. Stan — who played Carter Baizen on Gossip Girl — appeared in 11 episodes from 2007-2010. He's avoided publicly discussing his relationships over the years, but he spoke highly about Meester during their time together.