“So Kim thinks I’m 41,” Kourtney, 42, said on Sunday, April 18, via Instagram Story alongside the card from Kim. “I guess last year really didn’t count.”

Kim, 40, responded to the mistake on her own Instagram Story, writing, “My bad,” alongside a face-palm emoji.

Earlier in the day, The SKIMS founder did shower her older sister with more love. “Happy Birthday to my Armenian Queen @kourtneykardash! The person on this planet I’ve known the longest! The person that will try any beauty treatment with me LOL about Kourt…There’s NO ONE like you!” Kim captioned her birthday tribute filled with photos of the duo via Instagram.

She added, “You always know what you want in this life and will never conform to what others ideals are and I admire that so much! You always stick up for what’s right and have become the best therapist a girl could ask for! I love you too the end of time and beyond! Have the best birthday, you deserve it all!!!”

The Poosh founder celebrated her special day with many wonderful messages from friends and family, including boyfriend Travis Baker.

“I F—KING LOVE YOU! 🖤,” the Blink-182 drummer, 45, wrote via Instagram on Sunday. “YOU’RE A BLESSING TO THIS WORLD HAPPY BIRTHDAY @kourtneykardash.”

The social media message was only a small part of Barker spoiling his girlfriend on her special day, as he sent her a huge floral display at her home.

“Tulips and gardenias are my favorite flowers,” Kourtney captioned a photo of the arrangement via her Instagram Story. “My entire house smells yummy.”

The floral arrangement included white tulips and green moss in a vase with white gardenias hanging from the ceiling.

Us Weekly confirmed in January that Kourtney is dating Barker after years of friendship.

An insider told Us at the time that the duo “have been close friends for years and have been dating for a couple of months,” adding that the record producer “is very smitten with Kourtney and has been for a while.”

Barker was previously married to Shanna Moakler from 2004 to 2008 and the pair share kids Landon, 17, and Alabama, 15, together. Kourtney shares three children, Mason, 11, Penelope, 8, and Reign, 6, with ex Scott Disick. The Flip It Like Disick alum, 37, also wished Kourtney a happy birthday.

The performer and the Kourtney and Khloé Take Miami alum became Instagram official in February, posting a photo of themselves holding hands in a car after celebrating Valentine’s Day together.

Things have only gotten more serious since then, with the songwriter sharing an adorable handwritten note from Kourtney in late March.

Barker shared the note, which was signed with a heart, via his Instagram Story with a black and white photo. “I love you,” the sweet and simple letter read.

This story originally appeared on: US Magazine - Author:Yana Grebenyuk