"Shortly after Scott [allegedly] DMed Younes, Amelia and Scott were still trying to make New York Fashion Week plans together," the source said. "Scott was trying to write the situation off as nothing, but as the days went by, Amelia was more and more hurt by the whole thing."
The source said Hamlin had "been understanding of Scott's co-parenting routine and the family dynamic, but this disappointed her."
"They are figuring out where to go from here and what their future looks like," the source added.
In the alleged DM from Disick, there's a photo of Kardashian, 42, kissing and straddling Barker, 45. The message reads, "Yo, is this chick OK!???? Broooo, like what is this? In the middle of Italy."
Bendjima, 28, called the father of three out, posting the alleged DM to his Instagram account.
A source previously told ET that Disick was "salty" about his ex's new relationship with the Blink-182 drummer. Meanwhile, another source told ET on Friday that Hamlin "was definitely annoyed" by the DMs, and that Disick "is trying to move on from the whole situation, but is a little embarrassed that he reached out to Younes and that he posted their exchange."
As for Kardashian -- who shares 11-year-old Mason, 9-year-old Penelope, and 6-year-old Reign with Disick -- a separate source told ET that she and Barker "don’t care about Scott’s opinion, but Kourtney is upset it’s now public."