Kourtney Kardashian’s son Mason is officially a teenager — and taller than his aunt Kim Kardashian.
The KKW Beauty creator posted proof of the 13-year-old’s height via her Instagram Stories Wednesday.
“The day has come where you’re taller than me now,” Kim, 42, wrote to her nephew.
“I just love who you are and I’m just so proud of you Mason,” the “Kardashians” star continued. “Welcome to your teenage years. Happy birthday.”
Kim stood back-to-back with the teen in the social media upload.
Kourtney, for her part, honored both Mason and his brother, Reign, 8, in a post of her own as the siblings share the same birthday.
“December 14th … one of the best days of my life, twice and forever,” the Poosh creator, 43, captioned a throwback snap. “my birthday boys ❤️❤️.”
Kourtney, who is also the mother of 10-year-old daughter Penelope, welcomed Mason and Reign with her then-boyfriend Scott Disick in 2009 and 2014, respectively.
Disick, 39, honored his little ones with Instagram Story tributes Wednesday, too.
“Happy birthday 2 my better half,” the Talentless creator wrote. “Love you Mason. Nobu Nobu Nobu.”
In a second slide, the “Flip It Like Disick” alum added, “I think it’s safe to say Rayman liked his birthday gift. Love you son!!! You make my life a better place.”
Disick and Kourtney split in 2015, and the Lemme creator is now married to Blink-182’s Travis Barker and trying to conceive a baby.
While the Hulu personality underwent in vitro fertilization, she told the Wall Street Journal in September that she chose to pause her treatment.
“It was a lot. I took a break to just focus on our wedding and getting married,” she explained.
Earlier this month, Kourtney wrote via Instagram that she is “finally” getting her energy back 10 months post-IVF.
“For anyone else going through it, it gets better!” she concluded.
Barker is the father of son Landon, 19, and daughter Alabama, 16, with his ex-wife, Shanna Moakler. The 47-year-old musician also maintains a close relationship with his former stepdaughter, Atiana.
The Grammy nominee and Kourtney’s blended family is all she “could ever want,” the “Keeping Up With the Kardashians” alum gushed on her family’s show in May.
“The more kids, the merrier. It’s more people to love,” she said in a confessional at the time. “I am really close with Travis’ kids and I love them and it’s a beautiful thing.”