Sing out, Louise!
Opting for a casual but classy ensemble, Jenner wore a patterned turtleneck top and jeans, which she paired with a long black coat. Clearly in the birthday spirit, she also wore a small blue and gold-trimmed party hat around her head.
Hadid, 22, wore a black top and houndstooth pants alongside an equally festive red party hat.
Giving her followers a behind-the-scenes look at the celebration, Hadid also shared a video of the birthday girl singing along to the classic Shania Twain song “Still the One.”
Jenner went on to post a video of all of her pal, rapper Tyler the Creator, acting silly while singing along at the bash.
“Lmao I love my friends,” she wrote alongside the clip.
Earlier in the evening, Jenner’s pals appeared to throw her a low-key house party filled with animal toys and even a “homemade” cake.
In one image, shared by pal Justine Skye, 23, Jenner was seen holding what appeared to be an inflatable dog while wearing a black and pink feather boa around her neck. In the photo, Jenner was flanked by pals wearing silly costumes — one friend dressed like a bunch of purple grapes, while another wore a 3D costume that made it appear like they were sitting in a bathtub.
“Happy birthday bitch,” Skye wrote alongside the photo, appearing to reference a cake she gave the woman of the hour earlier, which was decorated with the same cheeky message.
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Earlier in the day, Jenner also showed off some of the beautiful flower arrangements that had been sent to her in honor of her big day — including a gorgeous box of pink and white roses by Venus ET Fleur that spelled out “KJ23.”
“Thank you,” she wrote alongside the shot.
The model also kicked off her celebrations by getting a sparkly cake from her pals, which appeared to lovingly refer to Kendall as “biiiiiiitch,” and relaxing in front of the television, watching “horse shows.”
Although none of her famous family members appeared to attend the N.Y.C. bash, they all made sure to post a series of loving tributes to the birthday girl.
“Happy Birthday @kendalljenner I’ve never met a sweeter or prettier human being and someone who has so much fun in life!” Kim Kardashian West, 38, wrote alongside an adorable throwback shot of her baby sister sitting in her lap back in the day.
“I hope you get everything you’ve ever dreamed of for your birthday because you deserve it! I’m so happy you are my sister. I love you,” added Kardashian West, who celebrated her own birthday on Oct. 21.
Jenner’s younger sister Kylie Jenner, 21, also got the throwback memo, posting a series of shots from the pair’s childhood. In one image, the sisters rocked matching hairstyles and matching dresses while smiling next to each other on a set of steps.
“Happy birthday to my partner in crime, my best friend, my sister! @kendalljenner i couldn’t have done it all without you,” she wrote, adding a red heart emoji.