Even if you've been keeping up, this pic might still catch you by surprise.
After all, Kim Kardashian recently shared family photos, and featured in the carousel was Kourtney Kardashian and Scott Disick's 13-year-old son Mason Disick, marking a rare sighting for the teenager.
In the photos, Mason holds up a peace sign while his dad drapes an arm around him. Also posing with the pair? Mason's sister Penelope Disick, 11, as well as cousins North West, 10, Saint West, 8, Chicago West, 5, and Psalm West, 4.
Kim simply captioned the Dec. 11 post, "Everything."
And her followers agreed, with many stunned at how grown up Mason looked. "Shut UP. why does mason look 17," commented one user, while another added, "Omg WE HAVENT SEEN MASON IN FOREVERRRRRRRRRRR!!!!! Our little internet nephew GREW UP!!!!!!!!!!!!"
But while he might be the internet's nephew, Mason also plays an important role in his IRL family: big brother. A role that became that much more important when Kourtney gave birth to her and Travis Barker's first child, Rocky Thirteen, in November.
Indeed, baby Rocky joined a large, blended family. In addition to counting Penelope as his sibling, Mason also is big brother to Reign Disick, 8. Plus, Travis is dad to Landon Barker, 20, Alabama Barker, 17 (with ex-wife Shanna Moakler) and stepdad to Atiana De La Hoya, 24.
It's a concept that has always appealed to the Poosh Founder, who tied the knot with the Blink-182 drummer in 2022.
"I love the idea of a blended family," Kourtney said during a confessional on season two of The Kardashians. "I think the more kids the merrier. You have all these siblings and more people to love, and it's a beautiful thing."
Keep reading for more of the Kardashian-Barker family's best moments.
Like Father, Like Son
Rocky Thirteen makes a cameo in his dad's photos from the Australia/New Zealand leg of Blink-182's world tour in March 2024.
Mom & Me Mirror Selfie
Penelope Disick appears with her mother on their family trip to Australia, during Blink-182's tour in February 2024.
Australian Summer
Reign Disick and Penelope Disick enjoy some fun in the sun during their family trip to Australia during Blink-182's tour in February 2024.
Kravis Down Under
Kourtney and Travis enjoy some touristy activities in Australia during Blink-182's tour in February 2024.
Boys Club
In honor of Landon's 20th birthday in October 2023, Kourtney shares a throwback photo from 2017 of the then-teenager hanging out with Mason.
Celebrating Dad
Travis is joined by Kourtney and Landon at GQ's Men of the Year party in November 2022.
A Fashionable Family
Kourtney and Travis take Alabama to Tommy Factory's New York Fashion Week show in September 2022.
Alabama snaps a silly selfie with half-sister Atiana annd Kourt and her daughter Penelope Disick during the Kardashians star's May 2022 wedding with Travis.
Kourtney takes a break from her wedding festivities in to pose for a selfie with Alabama.
Meet the Kardashian-Barkers
Travis Barker take daughter Alabama Barker, son Landon Barker and stepdaughter Atiana De La Hoya to the premiere of The Kardashians in April 2022. Meanwhile, Kourtney Kardashian is joined by her youngest son Reign Disick.
Front Row
Kourtney's oldest son, Mason Disick, tags along with Alabama and Atiana to Travis and Kourtney's front row outing at the AMIRI fashion show in February 2022.
Kourtney shares a close up of this sweet throwback of Alabama and Penelope for Alabama's 17th birthday.
Kourtney, Travis, Alabama, Atiana, Landon and Reign pose at Disneyland in April 2022 for Kourtney's 43rd birthday celebration.
Kourtney, Travis, Alabama, Atiana, Landon and Reign spend the day at the Happiest Place on Earth in April 2022 in honor of Kourtney's 43rd birthday.
Landon, Atiana and Kourtney strike a pose.
Penelope the artist! Travis shared her drawing of him in March 2022.
On Christmas Eve 2021, the Kardashian-Jenners join the Barkers for a night of celebrations.
Travis and Penelope enjoy a game of checkers, while Kourtney and matriarch MJ watch the pair.
For Alabama's 16th birthday in December 2021, Kourtney and Travis surprise her with balloons that spelled out BAMA 16. Her dad writes in the caption, "I LOVE YOU SO MUCH!!!"
Travis appears with Kourtney and Penelope in a TikTok video posted on the mom and daughter's joint account.
"So happy for you guys," Travis's daughter Alabama writes on a photo of the Blink-182 drummer and Kourtney as they celebrate their engagement. "I love u both!"
Landon joins his dad and Kourtney for some Halloween 2021 fun at Knott's Scary Farm in Southern California.
Seeking out more spooky scenes, Kourtney recruits her son Mason for a trip to Universal Studios' Halloween Horror Nights with Travis and his daughter Alabama in 2022.
Travis' stepdaughter and Alabama and Landon's half-sister Atiana De La Hoya pose as the Bride of Frankenstein to Reign's Frankenstein.
Kourtney's daughter Penelope rocks a devil costume for yet another family Halloween outing. This time, the crew heads to immersive L.A. jack-o-lantern experience, Nights of the Jack.
During their Nights of the Jack adventure, Alabama captures Travis and Penelope sharing a sweet moment as he walks around carrying her on his shoulders.
Even before they were dating, Travis and Kourtney were friends for years. Just look at this throwback photo of Mason, Landon, Alabama and Penelope from 2017 that the Keeping Up With the Kardashians star shared in honor of Landon's 18th birthday in October 2021!
Talk about a sweet birthday present! Travis gifted Kourtney's daughter Penelope a state-of-the-art drum set when she turned nine back in July 2021.
What better place to spend the Fourth of July 2021 than Disneyland? The happy couple celebrated the holiday there with Landon, Alabama and Reign.
Atiana opts to twin with Kourtney in matching snow gear during their first family trip together in Deer Valley, Utah back in April 2021.