Now, Mason (and the rest of Kourtney's kids) are growing right before our eyes!
If you keep up with the Kardashian's, then you also know that today marks both Mason and Reign Disick's birthdays. Specifically, Mason turns 10 today while his little brother turns 5! Dec. 14 is a special day for Kourtney and the rest of the Kardashian family as they celebrate these two sweet young boys.
Who knows what extravagant celebration the family may have up their sleeve for the two, but in the meantime, Mason's aunts and grandma are wishing him the best on Instagram.
Of course, the mother of three and Poosh founder also took to Instagram to share some sweet birthday shoutouts to her kids.
After reposting Simon Huck's Instagram Story of Mason—which he captioned "Happy birthday BOSS! We love you!!!"—Kourtney posted a video to her stories of the 10-year-old singing. "My baby is 10," Kourtney wrote alongside the video of Mason rapping along to a Travis Scottsong.