13 Things You Definitely Didn't Know About Gossip Girl

We could not imagine anyone else in the role of Serena, but the actress was initially hesitant to join the series. Lively's work on The Sisterhood of The Traveling Pants.

"We didn't see a lot of other girls for Serena," series creator Josh Schwartz said.

"She has to be somebody that you believe would be sitting in the front row at Fashion Week eventually." Lively later relented after first declining when she was told she could attend Colombia one day a week. It was never put in writing and it sure sounds like Lively did not get to go.

"This is advice to anyone: when they say, 'We promise, but we can't put it in writing,' there's a reason they can't put it in writing," Lively said with a laugh, "But no, the show didn't slow down. It just got more and more."

Leighton Meester was AMAZING as Blair Waldorf, but Chace Crawford seemed to think she was not the right person for the role.

"I just don't see her as Blair Waldorf. I can't see it," he said of Meester. But he saw it immediately when she got into character, thinking, "That girl can act. She's the perfect girl for this."

Schwartz said, "Obviously; Serena had to be blonde. So, [Leighton] went to the sink and dyed her hair. She wanted it."

Leighton originally auditioned as Serena, but she managed to convince them she would make a better Blair.

"I think it was just the normal, typical pilot season audition for me. I auditioned and then I tested once and then we did a screen test with everybody. And then, that was it ... I dunno. I got it," she said.

Like any popular TV series, there are always rumors that there is unrest on the set between the stars.

"When we were filming, there was, 'Leighton hates Blake, Blake hates Leighton, everyone hates Blake, everyone hates Leighton, everyone hates Chace,' and blah, blah, blah. It really wasn't," Michelle Trachtenberg said of the energy on set. "We were all chill. It was cool."

While Leighton and Blake may have gotten along, they were not as close as Serena and Blair.

According to executive producer Joshua Safran, "Blake and Leighton were not friends. They were friendly, but they were not friends like Serena and Blair. The second they'd be on set together, it's as if they were."

We already knew that Ivanka was a huge fan of Gossip Girl, but fans were surprised when she actually made an appearance on the show, but why did she take on a role?

"They did it for the money," Schwartz revealed with a laugh. Yes, we're going to bet he's totally kidding.

Considering the crazy rumors that appear about the cast members, Blake and Penn split in secret months before Joshua Safran found out on set.

"The shocking thing was, I found out on the set of the Season 2 finale that Blake and Penn had broken up months before," Safran said.

"They kept the breakup hidden from the crew, which you could never do now. I don't even know how they did it. They kept it from everybody which is a testament to how good they are as actors. Because they did not want their personal drama to relate to the show."

"I remember there was one point where we were just afraid of how our personal lives overlapping our work life could be perceived by our bosses. [But then] we were like, 'Oh no, that's exactly what they want,'" Lively said of the on-set hookups.

"They wanted us all to date. They wanted us all to wear the same clothes that we're wearing on the show. They wanted that, because then it fed their whole narrative. People could buy into this world."

It turns out, Penn was not a fan of being on the show.

"Penn didn't like being on 'Gossip Girl,' but ... he was Dan. He may not have liked it, but [his character] was the closest to who he was,' Safran said.

"Some of the actors were not entirely happy to be there after a certain point," Safran added. "And no matter what we did, they were never going be happy ... They were kids. They were young."

Once upon a time, Blake dated Leonardo Dicaprio. "We learned a lot from Blake," Safran said.

"When I think about shooting the L.A. episodes, Blake was dating [DiCaprio] at the time, and she had this thing where she had a doll that she took photos of that she sent to Leo. Blake was way ahead of the curve. It was pre-Instagram. She was documenting her life in photographs in a way that people were not yet doing."

"Of course. I'm open to anything that's good, that's interesting, and that sort of feels necessary," Lively said of returning to the franchise.

"If everyone was into it and if the timing was right, you know?," Meester added, "I don't want to say, 'No, never ...'"

Schwartz and Stephanie Savage added that they "could be persuaded [to revisit the world of Gossip Girl] if there were new stories to tell." We would be forever grateful for more episodes.