Kourtney Kardashian Attends On-Off Fling Luka Sabbat's 21st Birthday Party

Could Kourtney Kardashian and Luka Sabbat be heating up again?

Less than a month after PEOPLE reported that the couple had cooled off, Kardashian celebrated with Sabbat at his 21st birthday party on Monday night. The Keeping Up with the Kardashians star was spotted leaving the Peppermint Club in West Hollywood alongside the Grown-ish actor early Tuesday morning.

This isn’t the first time Kardashian, 39, and Sabbat have hung out since their fling apparently ended. In early November, the two were seen leaving Sean “Diddy” Combs‘ 49th birthday bash at Ysabel in L.A.

“Kourtney likes Luka,” a source previously told PEOPLE. “It’s never been serious though and never will be. She hooks up with him occasionally, but that’s it.”

Kardashian and Sabbat were first linked in September after her split from Younes Bendjima, 25, but a source told PEOPLE in October that the casual romance had run its course.

“Kourtney is no longer seeing Luka,” the source said. “It was a fun fling for her, but not a big deal. She has more important things to focus on, like her kids and her work.”

RELATED: Kourtney Kardashian Has a Sleepover with Scott Disick So They Can Spend Thanksgiving as a Family

November has been a busy month for Kardashian when it comes to spending time with her exes. The reality TV star also enjoyed a family sleepover on Thanksgiving with ex-boyfriend Scott Disick and their three kids: Mason, 8, Penelope, 6, and Reign, 3.

“I woke up this morning in bed with my children, in the same house as my sisters (minus @khloekardashian i miss you), my brothers, the father of my kids, my mommy, my grandma, my nieces and nephew. I feel beyond grateful. Happy Thanksgiving!” she captioned a sweet family photo on Instagram.

RELATED VIDEO: Scott Disick Says He’s in a ‘Different Place’ in Life: ‘I Can Have Fun and Still Hold Down a Job’

Kardashian also attended an L.A. art event with Disick and his girlfriend Sofia Richie, 20, earlier this month.

A source previously told PEOPLE that Kardashian “doesn’t necessarily care to get to know Sofia better, but she feels she needs to because of the kids.”

“Sofia spends time with Kourtney’s kids, so Kourtney wants to make sure they are all on the same page,” said the source. “Kourtney wants to make sure the kids are in a positive environment when they are at Scott’s house. She is setting up rules for how things need to be when the kids are with Scott.”