The two joined fellow family and friends at the festivities, which began at Craig's restaurant and ended with a big bash at Delilah in West Hollywood on Thursday night. Kourtney and Scott sat next to each other at a table. Khloe posted on her Instagram Story a video of the two, showing the two using phones.
"A girl can dream," Khloe captioned the video.
Kim Kardashian also posted a video of Scott and Kourtney sitting together, saying, "Oh, just like an old married couple, on your phones!"
Kourtney and Scott, who co-parent three children, have remained friendly since their 2015 breakup.
The party took place days after it was revealed that Kourtney and Younes had split after almost two years. A source told E! News earlier this week that "Scott is very happy Kourtney cut it off with Younes" and "never liked Younes for Kourtney," adding that he is happy in his own relationship with Sofia Richie.
Scott's girlfriend did not attend the bash. She has never been spotted at a Kardashian-Jenner event since she and Scott started dating last year, while Younes has.