'Stay a little forever' Kim K told North in a video as the toddler clocks 3 today

Kim Kardashian shared a sweet video to mark her daughter North's 3rd birthday today.

In the video, the 35-year-old is seen telling her daughter to 'stay little forever' while cradling her in her arms and planting a kiss on her cheek. 

She shared the video on Instagram, along with a caption that read: 

'She promised me she wouldn't get any bigger. I can't believe my baby girl is 3 years old today!!!! Northie I love you so much I can't even explain it! Happy Birthday to my favorite mermaid!!!'

Happy Birthday North..