While it's unclear if the pair will be spending the holidays together, the estranged couple were spotted out for lunch at Marmalade Café in Calabasas on Wednesday.
Kardashian, 36, wore an all white ensemble with black boots and dark sunglasses, while Disick, 32, went with a gray hoodie, dark jeans and a baseball cap. But while the pair was all smiles, an onlooker tells PEOPLE that "they were not affectionate in any way."
The former couple split this summer after nine years together. Since splitting, the relationship between the two has been tumultuous, as Kardashian has threatened Disick with ultimatums involving their three children, Mason, 5, Penelope, 3, and Reign, 11 months, if he didn't clean up his act.
Her threats perhaps served as a wake up call Disick, who recently checked into rehab and is working towards sobriety.
However, Disick revealed that he will be, once again, hosting a New Year's Eve party in Las Vegas.
He's out! Scott Disick's Belongings Find a New Home after Split from Kourtney Kardashian
"Something has clicked in his head. He's in a very healthy place, and he's being a lot more authentic than before," a source told PEOPLE about Disick earlier this month. "He used to give everyone what I call 'rehab speak,' where he was just repeating phrases that you know he heard in counseling somewhere.
"These days, he's being a lot more clear in what he's saying. He used to always talk about 'taking responsibility,' but now it seems like he's actually taking responsibility by trying to spend time with his kids."
The source also mentioned the positive turn Kardashian and Disick's relationship has taken.
"He's also talking to Kourtney in a more productive manner. They are talking to each other, not past each other," the source said. "Will he ultimately end up with her? I'm not sure about that. But at least they're being healthy as they interact, which is a lot of progress."