It seems as though things with Sofia Richie and Scott Disick have only gotten more serious since Kourtney Kardashian met with her ex and his girlfriend for dinner at Nobu in Malibu on Sunday, PEOPLE reports. Kourtney left in a separate vehicle and the publication details how the meetup was seen as necessary on Kourtney’s part, being as she and Scott share three kids together.

“Sofia spends time with Kourtney’s kids, so Kourtney wants to make sure they are all on the same page,” a source told the publication. “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 need to be when the kids are with Scott.”

The source added: “It was a quick dinner. It seemed a bit tense. It wasn’t like they are all friends and were hanging out for fun. It looked more like a business dinner.”

Scott joined Kourtney and their kids, as well as the extended Kardashian family, on their recent family trip to Bali after getting back from Austrailia with Sofia.