A fan quickly called out Kourt to point out that she failed to wish sister Kylie Jenner's daughter a happy first birthday.
"The most touching birthday wish for Stormi," the fan wrote. To which Kourtney replied, "She doesn't have Instagram yet, but Stormi if you're reading this Happy 1st Birthday!"
Instagram account Comments By Celebs caught the exchange:
It looks like Stormi had a perfect birthday, despite Kourtney's lack of Insta message. The Kar-Jenners celebrated the milestone with a rainbow-themed party complete with massive balloon centrepieces and a rainbow sprinkle cake.
Watch below: All the times Kylie Jenner has teased Baby No. 2.