Relations between the sisters have reportedly become strained this year, with their disagreement seemingly centring around Kourtney’s 2022 wedding to Blink-182 drummer Travis Barker.
The nuptials, which took place in Portofino in Italy, were curated by Dolce and Gabbana designers Domenico Dolce and Stefano Gabbana, who later partnered with Kim on their spring 2023 collection.
Kourtney, 44, argued that Kim, 43, had teamed up with the brand without speaking to her first, claiming that she had “used my wedding as a business opportunity” during an episode of their Disney+ reality show The Kardashians.
Sharing a throwback photo of her and Kim on her Instagram story, Kourtney joked that the pair’s “hair pulling, nail digging” fights during their adolescence were much worse than any disagreements that fans have watched on TV.
“Happy happy birthday to my first sister,” she wrote. “Thank you for all those years of bossing you around and you actually listening to all of my crazy ideas. People think the fights they’ve seen on TV are bad, if only they got to witness the hair pulling, nail digging ones from early high school.”
“The joys of sisterhood,” she added. “I love you deeply forever and always. May God bless this year with love and happiness and abundant joy.”
Her birthday message came after Kim revealed that she is part of a secret WhatsApp group where her family and friends can talk about Kourtney.
“All of your friends call us complaining,” Kim said in an episode of The Kardashians last month. “When you think they are the ones going to you, they are all coming to us on the side saying the opposite to us.
“So we are all confused and we are all on a group chat that is actually labelled ‘Not Kourtney’ so we know and have to funnel what your friends are saying to us.”
Kim even brought Kourtney’s three children Mason, Penelope and Reign into the argument, claiming that her nieces and nephews “have even come to me with problems that they have in how you are”.
Kourtney, who is currently expecting a baby with her husband, appeared to skip Kim’s birthday celebrations on Friday evening (20 October).
Her party was attended by family members including her mum Kris Jenner sisters Khloe Kardashian and Kendall and Kylie Jenner, as well as celebrity friends like Hailey Bieber and Sofia Vergara.