Bending the rules? Kourtney Kardashian attended Scott Disick‘s over-the-top birthday party on Monday, May 24. The founder, who shares kids Mason, Penelope and Reign with the E! personality, appeared to have a good time with the rest of her famous family and A-list guests like Sia.

However, now that Kourtney, 42, is dating Blink-182 drummer Travis Barker, she’s put “new firm boundaries in place” for Scott, 37, a source previously told Life & Style. The Talentless founder, who turns 38 years old on Wednesday, May 26, and the Keeping Up With the Kardashians star dated on-and-off from 2006 to 2015.

Scott Disick's Birthday Party: Photos With Kardashians, Amelia 8
Kourtney Kardashian/Instagram

Since then, Scott and Kourtney have been dedicated coparents and friends. That said, Kourtney distancing herself from Scott amid her romance with Travis, 45, has made things “awkward” between them, the insider noted, adding “it’s what’s best for everyone.”

When the former flames do get together, “they talk about the kids and figure out the kids’ schedules,” revealed the source. “There’s no room for added communication at all.”

Despite the growing pains, Scott, who is dating 19-year-old model Amelia Gray Hamlin, “understands how serious Kourtney and Travis’ relationship is,” the insider assured. “It’s definitely the most serious relationship she’s ever been in — aside from Scott — and some could argue it’s definitely the most mature relationship she’s ever been in in her whole life.”

Over the years, Kourtney and Scott have dated other people, but it’s never shifted their dynamic, including when the mother of three was in a relationship with Younes Bendjima from 2016 to 2018. “Each time that Kourtney was with another guy, Scott was not intimidated at all. In fact, she’d still invite him on family vacations and Scott felt that Kourtney’s boyfriends were probably more intimidated by him and their close bond than he was of them,” the source recalled. “But something’s different now.”

Ultimately, Kourtney still wants Mason, 11, Penelope, 8, and Reign, 6, to spend “as much as time as possible” with Scott, the insider said. “She’ll always root for Scott to be as happy and healthy as possible. However, because of how happy Travis makes her and how happy she is to spend time with him, she’s not going to share that time with Scott.”