In the photo, the mother of three can be seen throwing up the hang loose hand sign while wearing a turquoise bra top paired with green trousers. Meanwhile, Scott, 35, opted for a surf pose as Mason, 8, and Reign, 3, mimicked him.
Scott previously shared photos from their family trip on Instagram.
In one image, the pair’s daughter Penelope Disick, 6, appeared to be deep in thought while standing across from her cousin and BFF North West, 5. Kourtney’s sisters Kim Kardashian West and Khloé Kardashian were also on the trip with their children.
“Double the trouble,” Scott wrote alongside the image, adding three red heart emojis.
Scott went on to share another adorable photo of Penelope as she stood on a wooden set of steps during a boat trip. “Poosh,” he captioned the image, using the nickname both he and Kourtney have used many times in the past.
“Just sailing,” he captioned another image showing himself relaxing on the trip while North stood at the edge of the frame.
The exes, who ended their nine-year relationship in July 2015, did not share any photos of themselves together.
Disick and Richie, 20, who have been officially dating since last September, left the Malibu restaurant after dining together. Kourtney departed the hotspot in a separate vehicle.
A source previously told PEOPLE Kardashian “doesn’t necessarily care to get to know Sofia better, but she feels she needs to because of the kids.”
The source added, Sofia spends time with Kourtney’s kids, so Kourtney wants to make sure they are all on the same page. Scott and Sofia tend to get into arguments. 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 needs to be when the kids are with Scott.”