Kourtney Kardashian wishes sister Kim Kardashian a happy birthday

kim-kourtney-kardashian-birthday-kollection-lipsy-gi.jpgThose Kardashian sisters -- they're thick as thieves.

On Monday (Oct. 21), Kourtney Kardashian took to her blog to offer her sister Kim a heartfelt birthday wish on the new mom's 33rd birthday. With the headline "Happy Birthday Kiki," Kourtney presented a photo gallery of 38 photos of the "Keeping Up with the Kardashians" stars, alongside their sister Khloe. Accompanying the gallery was the caption, "I hope you have a very happy birthday and that all of your wishes come true. You are an incredible mother, sister, auntie and friend. I look up to you and learn from you every day. I love you!!"

Kim's birthday isn't the only thing the Kardashian sisters are celebrating, however. The three are taking their Kardashian Kollection fashion line into the high-fashion world, teaming up with UK retailer Lipsy to launch the Kardashian Kollection for Lipsy, which debuts Thursday.

In a recent interview with Hello magazine, Kourtney revealed how this new collection stand apart from the others. "We wanted to offer something different to what currently exists on the British high street," she says. "We spent a lot of time trend forecasting and collaborating on ways to design a fresh line of fashion-forward, affordable luxury. Kardashian Kollection for Lipsy will have some amazing stand out pieces like a full-lace jumper and metallic sequin jackets."

Birthdays, fashion line launch -- talk about a busy week.
Photo/Video credit: Getty Images