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.

Sebastian Stan fondly looked back at a romance during his Gossip Girl era, presumably with ex-girlfriend Leighton Meester. “It was the first time I was in serious love with somebody,” Stan, 42, told Variety in an interview published on Thursday,

Sebastian Stan has sent fans of the iconic TV show Gossip Girl wild as he revealed his first “serious love” was on the show. Sebastian reminisced about how he fell in love for the first time while on Gossip Girl. The actor made the shocking confession in a new interview with Variety.

It looks like Sebastian Stan meant every one of his xoxos to Leighton Meester. The Gossip Girl alum revealed that he feels particularly nostalgic about his role as Carter Braizen on the CW series from 2007 to 2011 due to the significance of his relationship at the time.