Watch: Kris Jenner Celebrates "Sweetest" Grandson Saint West's 10th BirthdayKris Jenner is showing off some of her grandsons' cutest moments. To celebrate Kourtney Kardashian and Scott Disick's sons Mason Disick and Reign Disick's birthdays Dec. 14, the Kardashian matriarch shared a bundle of rarely seen photos of the newly 16-year-old and 11-year-old. "Happy birthday to our birthday twins, my amazing grandsons, Mason and Reign!" Kris wrote in a Dec. 14 Instagram post. "You both have your own unique magic and you make our family so proud just by being who you are.