Sofia Richie helped Kylie Jenner cope after her feud with Jordyn Woods, and the pair now have an "irreplaceable bond".
The 21-year-old lip kit mogul fell out with her former best friend after she kissed Tristan Thompson at a party in February, while he was still in a relationship with Kylie's half-sister Khloe Kardashian, with whom he has 15-month-old daughter True.
And now, sources say Kylie new friendship with Sofia - who is dating Scott Disick, the ex-boyfriend of Kourtney Kardashian - was forged after the 20-year-old model helped her through the "emotional rollercoaster" that followed Jordyn and Tristan's scandal.
One insider said: "Sofia really helped Kylie through the emotional roller coaster during the Jordyn situation. She was really there for her and took her side through everything. The situation with Jordyn made them closer."
The "Keeping Up with the Kardashians" star is also said to "trust" Sofia around her 17-month-old daughter Stormi, which has created an "irreplaceable bond" between the two pals.
The source added: "Kylie also trusts Sofia around Stormi, which is very important to her. Sofia has been around since Stormi was born and Kylie feels comfortable with having her around her child after getting to know her better. They have now formed an irreplaceable bond."
Now, Kylie and Sofia hang out whenever they can, and the source insists they love having "girls' nights" at home or on the town.
They said: "Kylie loves how fun Sofia is and has been inviting her over to her house more often to hang just the two of them. They love staying home and watching movies and cooking together while hanging with Stormi. Kylie knows whenever she wants a girls' night out on the town, she can always count on Sofia for a good time."
The new friendship is even a hit with Kourtney - who has Mason, nine, Penelope, seven, and Reign, four, with Scott - as she too is on good terms with Sofia.
Speaking to E! News, the source said: "Kourtney is thrilled that Kylie has found a bond with Sofia. She thinks it's great for Kylie and loves that everyone can get along and spend time together. She has seen firsthand how much of a support system Sofia has been for Kylie, and it makes Kourtney feel even better about her dynamic with Sofia as well. There is no more awkwardness or tension like there was a year ago."