Kourtney Kardashian shared a flashback image to her POOSH Instagram account on Wednesday.The 41-year-old Keeping Up With The Kardashians star looked toned and trim as she posed while in a black-and-white string bikini by a swimming pool in a photo taken by her sister Kendall Jenner.This comes after the mother-of-three said she was embracing her quarantine curves after admitting to gaining a bit of weight under lockdown.