Gossip Girl was one of the most popular teen dramas during the late 2000s. Based on the novels of the same name by Cecily von Ziegesar, the series followed Serena van der Woodsen, Blair Waldorf, Nate Archibald, Chuck Bass, Dan Humphrey, and Jenny Humphrey whose personal lives are constantly scrutinized and commented on by the titular anonymous blogger. Relationships were a core story element of the show. While several of the romantic entanglements were problematic, the friendship between Serena and Blair was the most toxic. 

The Toxic Foundation of Serena and Blair’s Friendship 

Although the series often sold Serena and Blair’s friendship as extremely close, the girls spent most of their time keeping secrets, harboring jealousy, and outright trying to sabotage each other. The toxicity in their bond was first seen in Season 1, Episode 1, titled “Pilot,” which revealed that Serna had slept with Blair’s boyfriend, Nate. She then abruptly left for boarding school before without saying goodbye to her best friend. The secrecy surrounding her departure from the Upper East Side was the main point of contention in their relationship long before Blair found out about Serena’s tryst with Nate. 

However, Blair is not an innocent victim in the friendship. When she finds out about the affair and the reason for Serena leaving, she vows to take her down. Season 1 is filled with each girl (mostly Blair) plotting vicious attacks on each other to destroy their social standing at school and in the community. Their rift eventually resolves, and temporary peace follows. But things turn chaotic in Season 1, Episode 11, titled “Roman Holiday when Blair tells everyone that Serena went to the Ostroff Center for rehab, not knowing it was actually Serena’s brother being treated for depression. 

The Intensifying Rivalry and Sabotage 

In Season 2, Episode 6, called “New Haven Can Wait,” Serena and Blair each tried to sabotage the other’s Yale acceptance. The toxicity took center stage during an event for prospective students hosted by the University’s Dean when Serena intentionally steals Blair’s answer to a question he posed. When the group was asked who they would most like to have dinner with, Serena named the Dean’s favorite writer, George Sand, knowing full well that it was going to be Blair’s response. The move hurt her best friend, who was compelled to retaliate by blurting out that Serena had killed someone.

While Serena was technically responsible for the death of a man named Pete, it wasn’t exactly murder. His death was an unfortunate accident at the hands of manipulative young socialite Georgina Sparks, who wanted to videotape Serena in a compromising position with Pete. But things went sideways, and Pete ended up taking too many drugs and overdosing. Although Serena was the innocent party in the incident, it had a massive effect on her. While Blair sympathized with her friend when she found out about it, she weaponized the information when it suited her. 

The Ultimate Betrayal and Supposed Truce 

Their rivalry continued throughout the series, with stolen photo shoots, banishment, job sabotage, orchestrated public embarrassment, and deeply personal insults being some of the highlights. But 

whether it was intentional or not, Serena always managed to get the upper hand or outshine Blair, with that latter constantly left to play catch-up. That’s probably why she eventually decided to date Dan in Season 5, Episode 17, “The Princess Dowry, even though she made her dislike for him known whenever the opportunity presented itself in prior seasons. 

While her friendship and subsequent romance with Dan felt organic at the time, he was never Blair’s type. She knew it would hurt Serena and throw their friendship into chaos. But she did it anyway, and Serena retaliated by sleeping with Dan. One can’t help but wonder if Dan, who was hiding in plain sight as Gossip Girl, used his platform to manipulate the girls so that he could be with Serena in the end. If that was the entire point of creating the anonymous persona, it worked. Dan and Serena were married during the series finale, and the girl’s “friendship” seemed to be on solid ground in that moment.