"Travis is so in love and infatuated with Kourtney. They're having the best time together. He's 100 percent all in and totally sees a future with her," the source said. "Kourtney is living her best life and is truly so happy. Having Kourtney and Travis get so serious has been an adjustment for Scott. He is still trying to get used to it. Scott is still close with Kourtney, but things between them have changed a bit."
"Happy birthday to the best mom a child could ask for and some more!" Disick captioned a family photo with Kardashian and their three kids, Mason, 11, Penelope, 8, and Reign, 6.
The post came after Barker shared a PDA-heavy post in honor of her special day.
"I F**KING LOVE YOU! 🖤 YOU’RE A BLESSING TO THIS WORLD," Barker captioned a series of photos of him kissing Kardashian as well as a video of her sucking on his thumb. "HAPPY BIRTHDAY @kourtneykardash."
"This is the happiest Kourtney has been in a while and her family is thrilled for her," a source told ET of the couple earlier this month. "Kourtney and Travis' kids get along great and all have the best time together. Kourtney's been trying to keep their relationship as private as she can on social media, but they're both super into each other and cute together."