American reality TV star Kim Kardashian penned an adorably sweet note for son Saint West who rang in his fifth birthday on Saturday.

The 'Keeping Up with The Kardashians' star hopped on to Instagram to pen sweet wishes for her son. Kardashian also revealed a ritual that she does on every birthday of her kids, i.e.- She asks questions about life to her children and records them on a video camera - to show it to them when they grow up.