We learned all kinds of unexpected insider info as Gossip Girl approached the 10th anniversary of its premiere 鈥 which just happens to be today! 鈥 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鈥檚 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鈥檚 descent into darkness, which coincided with portrayer Taylor Momsen鈥檚 changing tastes off-screen. 鈥淚 would say Jenny鈥檚 transformation to a darker character wouldn鈥檛 have happened had Taylor wanted to be Jenny,鈥 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: 鈥淚t 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鈥檛 dye Taylor鈥檚 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.鈥

Momsen ultimately decided she didn鈥檛 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. 鈥淪he was going to appear as herself,鈥 Safran revealed. 鈥淚t was around the time of a record release of hers, and she had too many obligations so we couldn鈥檛 make it work.鈥

The show also had to bail on another real-world crossover involving the Met Ball. 鈥淲e got really close, but it was just too complicated and secretive to shoot at the Met Ball,鈥 Savage explained. (The event has strict rules about taking pics and/or videos inside.) 鈥淭hey 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鈥檛 aired on TV yet.鈥 But oh, what might have been. As Savage put it, 鈥淭hat would have been the brass ring of Gossip Girl episodes.鈥

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鈥檚 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)