Penelope Disick and North West Speak ‘Secret Language’ in Cute Video Posted by Kim Kardashian

Happy birthday to my little mermaid! Seeing the magic in the world through your eyes makes me so happy.

A post shared by Kourtney Kardashian (@kourtneykardash) on

Just us girls! Penelope Disick and North West adorably babble at each other in a video that proud mom Kim Kardashian shared to Instagram on Friday, July 8, in honor of her niece's 4th birthday.

“Whatever secret language u girls speak, the way you girls protect each other & love each other is so special,” the 35-year-old reality star captioned the cute clip. “Penelope, North is so lucky to have a best friend like you! Happy Birthday my sweet P. I love you to the moon and back!”

In the video, Penelope and her cousin North, 3, both stand on chairs at the table and grasp each other’s hands as they laugh and speak gibberish to each other.

The tiny tots smile for the camera, and Penelope’s older brother, Mason, 6, can be seen peeking his head out from across the table from time to time.

Kourtney Kardashian also shared her sentiments about her little girl in a sweet Instagram post on Friday.

“Happy birthday to my little mermaid!” she captioned a photo of Penelope in a mermaid costume sitting on top of a table. “Seeing the magic in the world through your eyes makes me so happy.”

The BFFs celebrated their birthdays together at a joint mermaid-theme party on Saturday, June 18, wearing matching costumes inspired by The Little Mermaid.

Khloé Kardashian even donned a lavender wig at her little nieces’ request, and in Snapchats shared by Kylie Jenner, the entire Kardashian-Jenner clan happily rang in the duo’s birthdays with individual, lavishly decorated cakes.

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