Kourtney Kardashian Reacts to Son Mason Disick Officially Joining Instagram

You may have been one of the millions of people who watched Kourtney Kardashian give birth to son Mason Disick. Now, 14 years later, you can follow him on Instagram.

The eldest of the three kids the Lemme founder shares with ex Scott Disick officially joined the social media platform May 25, with a verified solo account, and his mother soon shared her thoughts.

"My first baby is on insta," Kourtney, who also shares baby boy Rocky Barker, 6 months, with husband Travis Barker, wrote on her Instagram Stories, linking to Mason's first post, "and I'm not OK."

On his first official day of Instagram, the teen shared three posts containing several pics of himself, family and friends. The first shows Mason posing alone on the deck of a cabin. The second includes a pic of himself standing with three of his friends and an image of him shopping and getting ice cream with sister Penelope Disick, 11, with the caption, "Fam." A third post, captioned, "Pics is all we know," contains a bathroom mirror selfie of Mason with their little brother Reign Disick, 9.

Kourtney, who has for years shared a TikTok account with Penelope, was not the only Kardashian-Jenner family member to get emotional over the teen officially joining Instagram. Her sisters Kim Kardashian and Khloe Kardashian also shared their thoughts.

"I can't believe my @masondisick is on insta," the Good American founder wrote on her Instagram Stories. "The one who named us Kiki and KoKo is a legit teenager."

Khloe also commented on Mason's first post, "I can't believe this is happening."

Kim, who shares a TikTok with daughter North West, 10, wrote to their nephew, "You're really on Instagram."

This is not the first time Mason has joined social media but it is the first time his parents have allowed it. In 2020, the then-10-year-old opened Instagram and TikTok pages that went viral before they were deleted. "Mason started some secret accounts during quarantine," Kourtney told Miranda Kerr the following year in a chat for Vogue Paris. "Those were quickly shut down."

Mason, whose birth was documented on the season four finale of E!'s Keeping Up With the Kardashians in 2010, has largely kept out of the spotlight in recent years and has rarely appeared on the family's current docuseries The Kardashians. However, the 14-year-old, the eldest of Kris Jenner's 13 grandchildren, has during that time occasionally been spotted in family photos shared by his parents and other family members on social media.

Scott recently offered some insight into Mason's life as a teenager as well as their father-son relationship.

"He's great, he's really been unbelievable," the 41-year-old said on the season five premiere of The Kardashians, which began streaming on Hulu May 23. "We're closer than ever." (For a look at every can't-miss moment from the Kardashian-Jenner family, watch Kards Katch Up.)

Scott also told Kris that Mason has also been looking forward to an extra special present when he's older.

"He's extremely excited about that new car," the Flip It Like Disick alum, "you promised him in three years."

Look back at pics of Kourtney and Scott's kids Mason, Penelope and Reign over the years...

Mason opened his first official Instagram account May 25, 2024.

After joining Instagram, Mason shared three posts, including one containing pics of himself hanging out with his sister Penelope.

Mason also shared this mirror selfie of himself with little bro Reign.

Scott shares a pic of his and Kourtney's three kids, Mason (left), Reign and Penelope on his Instagram Stories in January 2024.

Scott and his eldest kids Mason and Penelope appear with aunt Kim Kardashian and her kids North, Saint, Chicago and Psalm in December 2023.

What's the point of being a parent if you can't embarrass your kids? Reunited with his kids after Kourtney and Travis Barker's May 22, 2022 Italian nuptials, Scott posted an adorable pic of a sleepy Reign on his Instagram Stories.

Scott, Mason and Penelope are joined by family friends for a night full of fun, as Scott captioned his Insta story pic, "Got my crew with me."

At 9 years old, Penelope poses for a sweet selfie with Scott, which he captioned, "My little girl is getting so big I can't take it!"

Scott shares another sweet photo with his daughter, this time giving her a loving kiss on the head.

Reign, Mason and Penelope are joined by cousin North at their bracelet-making and lemonade stand. Dad Scott even received a custom "Lord" bracelet from Penelope! "Thanks pooshalini," he joked on Instagram Stories. 

Reign, Penelope and Mason play tag on the beach in a sweet pic shared by Scott on July 18. 

Scott shares a suntanning pic on his 39th birthday featuring kids Reign and Penelope in their backyard. "Happy bday," Scott captions the Instagram Story in May 2021.

Scott wishes Kourt a happy 42nd b-day on Apr. 18, 2021. "Happy birthday to the best mom a child could ask for a some more," he writes with a sweet family photo.

"Love and happiness," Kourtney wrote during a weekend getaway to Santa Barbara with her kids in August 2020.

"Pool party," Scott writes on this photo of Mason and Reign.

"Another day another poosh pose," the father of three quips about his daughter.

"I got 10 on it," Scott writes alongside this playful snap of Reign. 

"My little precious," the Flip It Like Disick star writes.

"My loves," Scott declares.

The eldest Kardashian shares to Instagram this cute snap of son Reign.

Kourtney and Mason have a ton of fun goofing around on TikTok.

Reign is rockin' around the Christmas tree(s) in this action shot shared to Instagram in December 2019.

"Not sure who has more fun @disneyland #disneyland #HolidaysBeginHere"

Throwback! "Just two cowgirls loving life! #kuwtk," Khloe captions this selfie from the family's Wyoming trip, which played out on The Kardashians.

"My silly baby is 5 years old today," Kourtney shares on Saturday, Dec. 14, 2019. "Life has so much more meaning with this wild, sensitive boy who has shown me the world through such different eyes."

Both of Kourtney and Scott's boys were born on December 14, but it was their eldest who celebrated double digits in 2019. "Happiest tenth birthday to the boy who changed my heart forever. No one is cooler or sweeter than you," his mom writes on Instagram. 

Reign rests on Kourtney after a busy day planting trees.

Penelope and Reign have a sweet sibling moment while at TreePeople in Los Angeles.

"We spent our morning planting trees with @treepeople_org," Kourtney shares on Instagram. "Thank you @futureearth for including us in such a beautiful morning taking care of our Earth."

Scott couldn't love his daughter and his dog more. "My little ones," he writes.