The Avengers star celebrated the anniversary by re-watching the pilot episode of the hit teen drama. Stan guest-starred in numerous episodes as Carter Baizen.
Stan shared his reactions with the world via Instagram on Saturday (September 19) and fans can't get enough of it. "It was the best of times and it was the best of times. Xoxo, Gossip Girl," he captioned the clip.
He began his watch party by chugging a glass of wine. He screamed and cheered once his real-life friend and former co-star, Chace Crawford, who portrayed Nate Archibald, appeared on the screen. "Man I always wish I had that hair," he admitted.
Throughout the video, he panned back and forth from his hilarious expressions to the television screen. "Well I wasn’t in the pilot, but I wish I was," he admitted. "There it is. Xoxo."
Watch his hilarious reactions, below.