TV drama aside,Ethermac a sister's love never wavers.

Kourtney Kardashian shared a heartfelt tribute to Kim Kardashian on her 43rd birthday Oct. 21.

"Happy happy birthday to my first sister @kimkardashian!" the Poosh founder, 44, wrote on her Instagram Stories. "Thank you for all those years of bossing you around and you actually listening to all my crazy ideas."

Kourtney continued, "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. I love you deeply forever and always. May God bless this year with love and happiness and abundant joy."

Over the past few months, The Kardashians has depicted a feud between the sisters that stemmed from Kim's 2022 collaboration with Dolce & Gabbana that was launched months after Kourtney married Travis Barker in Italy in a wedding hosted by the fashion duo.

On the Sept. 28 premiere of season four of the Hulu reality series, the siblings got into a heated fight during which the SKIMS founder alleged that Kourtney's friends "call us complaining" about her and that she and them were on a "group chat that's actually labeled 'Not Kourtney.'" Kourtney then called her sister a narcissist.

Kourtney posted her birthday tribute to Kim on a cropped version of a photo of the pair, which she had first shared on Instagram in 2015. The original pic shows the two with sisters Kendall Jenner and Kylie Jenner at a dinner celebrating their mom Kris Jenner's Haute Living magazine cover. In honor of Kim's special day, Kourtney also posted on her Instagram Stories several more throwback photos of the pair, including pics of the two as kids.

Kim celebrated her 43rd birthday with friends and family at a dinner in Beverly Hills. Kourtney, who is in the third trimester of her pregnancy with her and Travis' first child together, was not spotted. See pics of Kim and her guests arriving at the event below:

For the latest breaking news updates, click here to download the E! News App