The 34-year-old television personality brought his three children with ex-partner Kourtney Kardashian -- 8-year-old son Mason, 5-year-old daughter Penelope and 3-year-old son Reign -- on his trip to Mexico with Richie.
People reported Wednesday that Disick and Richie, the 19-year-old daughter of singer Lionel Richie, are staying at Chilean Bay Resort & Residences.
"Scott, Sofia and his kids flew to Cabo San Lucas via private jet," a source told the magazine.
"[They're] having fun in the sun," the insider said, adding that Disick, Richie and the kids have been "swimming in the pools and enjoying the resort."
Disick cozied up to a bikini-clad Richie in a photo he shared Wednesday on Instagram Stories. The picture shows Richie holding Disick's hand as she nibbles on a piece of licorice.
Richie, who brought her new puppy on the trip, had posted a photo Monday on Instagram of herself embracing Disick on the steps of a private plane.
"My [heart]," she wrote.
Disick and Richie confirmed their relationship in September after months of dating rumors.
People reported in February that Kardashian, who split from Disick in 2015 after nine years of dating, initially disapproved of the couple's relationship.
"The initial reaction from Kourtney when she found out that Scott was dating Sofia was not positive," a source said. "Like most people, she thinks Sofia is way too young for him and doesn't get it."
"She never thought Sofia was going to meet her kids," the insider added. "But now, Sofia spends a lot of time at Scott's, so Kourtney allowed her to meet the kids. She has met them a few times."
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