Kourtney Kardashian and Scott Disick found it "challenging" to co-parent their tots when they first found love in new relationships.
Scott Disick and Kourtney Kardashian in 2012
The 40-year-old reality star and her former partner have Mason, nine, Penelope, six, and Reign, four, together, and have been co-parenting their brood since they split in 2015.
But although they've found a good balance now, they admit things weren't always easy, as they struggled to co-parent effectively once Kourtney began dating Younes Bendjima - whom she romanced from 2016 to 2018 - and Scott followed closely behind with new love Sofia Richie, whom he has been dating since May 2017.
Kourtney said: "I think the hardest part was when we both started new relationships. That caused fights between you and I - about introducing the kids [to our new partners]. I think that caused the most challenges."
To which Scott added: "It's one of those things you don't think is ever going to happen, but like everything in the world, you know, things move [on]."
The 'Keeping Up with the Kardashians' stars also admitted to having been to therapy together to learn to "communicate" better.
Kourtney revealed: "I think that was like the time that you and I ... literally had to go to therapy to talk, to even be able to like, communicate together."
And Scott, 35, says they've now learned what's "appropriate" to talk about with each other, and they're in a "really good place" as co-parents.
Speaking in a video for Kourtney's lifestyle website Poosh, he said: "I think the biggest challenge was just trying to figure out how we separate ... our relationship as friends and parents and still be on the same page and what is, I guess, appropriate and what's not and when to be able to talk to each other.
"In the beginning, I think you set good [boundaries,] and then we learned from that and we've gotten to a really good place."
Tagged in Kourtney Kardashian Scott Disick