We learned all kinds of unexpected insider info as Gossip Girl approached the 10th anniversary of its premiere — which just happens to be today! — including the fact that Blake Lively used to take pics of a doll on set to send to her then-boyfriend Leonardo DiCaprio, and the mind-blowing detail that Jennifer Lawrence auditioned to play Serena van der Woodsen (a role that Lively initially turned down). Recently, the show’s co-creators, Josh Schwartz and Stephanie Savage, along with executive producer Joshua Safran, sat down with Vulture to share even more behind-the-scenes trivia about the drama-filled series.

One hot topic of discussion? Jenny Humphrey’s descent into darkness, which coincided with portrayer Taylor Momsen’s changing tastes off-screen. “I would say Jenny’s transformation to a darker character wouldn’t have happened had Taylor wanted to be Jenny,” Safran admitted.

Momsen, who was going through her own metamorphosis with her band Pretty Reckless at the time, directly influenced the evolution of her GG character, Safran explained to Vulture: “It was hard at a certain point to write for the old Jenny; we had to write for the new Taylor. Taylor wanted her hair a certain way because she was in the band and that was who she was, so we couldn’t dye Taylor’s hair to be Jenny every day, especially when she had events where she had to be Taylor for the weekend. So Jenny had to change.”

Momsen ultimately decided she didn’t want to act anymore, which led to her leaving the show in season four to focus on her band.

Speaking of musicians, there was one singer who wanted to appear on the show but never got the chance: Katy Perry. “She was going to appear as herself,” Safran revealed. “It was around the time of a record release of hers, and she had too many obligations so we couldn’t make it work.”

The show also had to bail on another real-world crossover involving the Met Ball. “We got really close, but it was just too complicated and secretive to shoot at the Met Ball,” Savage explained. (The event has strict rules about taking pics and/or videos inside.) “They were adamant that the Ahh! moment when people walked through the doors could not be spoiled by a production crew having been there, even if it hadn’t aired on TV yet.” But oh, what might have been. As Savage put it, “That would have been the brass ring of Gossip Girl episodes.”

Of course, even without the Met Gala episode that never was, we still have plenty of fond memories to look back on as we celebrate the show’s 10th anniversary.

Read the full Vulture story (which is packed with even more insider info) here.

What was your favorite Gossip Girl story line? Let us know @BritandCo!

(Photos via Kevin Winter/Getty + Scott Gries/Getty)