Kourtney Kardashian has made mouths drop with raunchy Instagram pic

Photo: Instagram/kourtneykardash

Photo: Instagram/kourtneykardash

Kourtney Kardashian is one hot mumma!

On Monday the reality TV star turned 38 (even tho she defs looks 28) and it appears she had a fab day with the fam-bam:

But Kourtney then shrugged off her "Mum" title by posting this wee birthday present to her followers:

birthday suit

A post shared by Kourtney Kardashian (@kourtneykardash) on

Girl is KILLING it!