It was a big deal, because back in 2014, they stopped being friends. In fact, they were really good friends before their feud!
They even went out together to Coachella in 2014, where Kylie captioned an Instagram photo of them with, "MY FAVORITE PEOPLE 🌼🌺🌸."
But the fight, like many other girl fights in history, was about a boy. A Justin Bieber boy to be precise.
At the time, Selena was dating Justin, and according to "source", Kylie was connecting to Justin. While Us Weekly reported at the time that Selena had "no issue" with the connection, TMZ also reported that Sel thought Kendall and Kylie were "bad influences" on Justin.
The drama was actually never addresses, but at the time Selena unfollowed Kylie on social media. They never remained close friends after that scandal.
However, yesterday's Met Gala brought them back together, and fans were living for it.
After posing for the cameras together, people began tweeting.
"SELENA AND KYLIE?!?! I THOUGHT THEY WERE OVER IM DEAD."
Another wrote, "kylie jenner and selena gomez together saved my whole life."