Kourtney Kardashian quits KUWTK following fight with Kim in season 18 opener

Things soon got physical between the pair, with Kim kicking and slapping her older sister, leading Khloe to have to jump in and break up the row.

Viewers couldn't believe their eyes, as they took to social media to voice their concerns, with many taking Kim's side.

But when one user wrote: "[Kourtney Kardashian] just needs to quit the damn show! I'm over her not wanting to film," Kourtney quote-tweeted and said: "I did. Bye."

Another wrote: "Does anyone apologize or correct their tone or words when they’re being mean to Kourt? Cause I'm not seeing that," to which Kourtney replied: ""Never. They actually don’t see where my hurt comes from."

Elsewhere on Twitter, the oldest Kardashian sister said: "It's been years of build up."

Revealing that the fight might have had something to do with her decision to leave, Kourtney also wrote: "It is from our darker moments where growth happens."

Earlier this week, Kim appeared on The Tonight With Jimmy Fallon show where she opened up about their explosive bust-up, telling the host her sister had an "attitude" during filming because she didn't want to be there.

She said: "She's not the type of person to make a decision and say, 'OK guys, I'm not gonna film,' but she'd come to work with an attitude every day, take it out on everyone from the crew to us and wouldn't make that decision."

Kourtney has spoken about leaving in the past, after Kim threatened to have her fired in season 17 because she was keeping things off the show.

Speaking on Entertainment Today, she said: “I just decided to spend more time as a mom and put more of my energy there.

“But I’m not saying goodbye… I think you’ll have to see more of it on the new season, season 18. It isn’t airing yet, but it’s being filmed. Currently, in this room.”

We guess the time has finally come to say goodbye!

Keeping Up With the Kardashians is available on E! and hayu. If you’re looking for more to watch check out our TV guide.