It is time to begin maintaining with teenage Mason Disick.

Kim Kardashian shared a snap of her nephew Mason in honor of his thirteenth birthday—and in honor of the truth that he’s all grown up.

“The day has come the place you are taller then [sic] me now,” Kim wrote on her Dec. 14 Instagram Story. “I simply love who you’re and I am simply so happy with you Mason. Welcome to your teenage years. Completely satisfied Birthday.”

Kim paired the candy message with a photograph of herself and Mason standing again to again. And sure, as seen within the snap, Mason is a bit of taller than the blonde-haired SKIMS founder.

As for the way {the teenager} celebrated his special occasion, dad Scott Disick—who shares Mason, son Reign, 8, and daughter Penelope, 10, with ex Kourtney Kardashian—gave followers a glimpse into Mason’s birthday dinner by posting a photograph of occasion friends seated at a desk at Nobu.

“Completely satisfied birthday 2 my higher half,” Scott wrote on his Dec. 14 IG Story. “Love you mason.”