Kourtney Kardashian is jokingly mourning the fact that her eldest child is no longer a baby and is a teenager with his own Instagram account! Mason Disick, who is Kardashian's eldest child she shares with ex-boyfriend Scott Disick, has officially joined the social media platform and has already posted three photos on his account.

“My first baby is on Insta and I’m not OK,” Kardashian wrote on her Instagram Story responding to Mason's first post adding several emojis describing how she felt about her son joining the social media platform.

The Lemme founder wasn't the only one that reacted to the news of Mason joining Instagram. Mason got the support from his father Scott and his aunts Kim Kardashian and Khloe Kardashian, who all “liked” the photo of him hiding his face with a baseball cap and looking down as he wore a dark t-shirt and baggy pants.

Kim also commented on the photo in disbelief: “You’re really on Instagram.”

Khloe added the photo to her Instagram Story, writing: “I can’t believe my @masondisick is on Insta. The one who named [Kim and I] Kiki and Koko is a legit teenager.”

Kourtney also recently commented: “My first baby [emotional emoji]”

What Has Mason Disick Posted On Instagram Since Kourtney Kardashian's Post?
Kourtney Kardashian with Instagram logos and sad face emojis

In addition to his Instagram debut photo, he has also shared two separate carousel posts. The second post contains a photo of his friends standing against a wall holding Jaded London shopping bags, a photo with his younger sister Penelope walking down a street as she wears a leopard print jacket and him in a grey Supreme jacket with their backs turned to the camera, the last photo in that post is him and Penelope again enjoying ice cream. He captioned the photo, “fam.”

The third post is a photo of him with his younger brother Reign taking a mirror selfie, two additional photos with him and a friend standing in front of a mirror. Mason captioned the photo, “[mirror emoji] pics is all we know.”

Scott commented on the photo, “Kids [red heart].”

Most of Mason's childhood was documented on Keeping Up With The Kardashians, which ran from 2007 to 2021. His birth was a notorious moment on the show, and Kourtney subsequently “pulled” him out. With the family's new show on Hulu called The Kardashians, Mason has taken himself out of the limelight and is very rarely seen in episodes, just like his uncle Rob Kardashian, who was in the original series.

Mason is the oldest of Kourtney's children whom she shares with Scott. The two also share daughter Penelope and son Reign. Kourtney recently gave birth to her fourth child a son, Rocky Thirteen, whom she shares with her husband Travis Barker.