Leighton Meester is Sebastian Stan Sexy

Gossip Girl cutie Leighton Meester (in YSL) shares a sweet moment with actor boyfriend Sebastian Stan at the Season 2 premiere of Gossip Girl at the upscale Henri Bendel boutique in midtown Manhattan on Sunday night.

Sebastian, who turned 25 earlier this month, had two small appearances on Gossip Girl as wealthy bad boy Carter Baizen (pictured below). It would seem that hooking up on the Gossip set is the way to do things these days! (Ahem, Blake Lively and Penn Badgley.)

Leighton, 22, and Sebastian, 25, have been dating for at least several months now and were spotted holding hands in public last month.

45+ pictures inside of Leighton Meester looking Sebastian Stan sexy…