"Palm Springs disposable 2020" Kourtney captioned the collection of snaps.
It comes after sister Khloe came under fire when an unedited bikini photo of herself was uploaded by her grandmother Mary Jo 'MJ' to Instagram.
After the photo made its way to the internet, Khloe and her team reportedly did everything in their power to remove it.
Fans praised the "beautiful" snap for showing a different, more relaxed side of the reality star than the image she usually presents to her 136 million Instagram followers. By way of contrast, here she is in a photo posted to her official Instagram account:
Kardashian family representatives went into overdrive as the offending bikini photo circulated.
"The colour edited photo was taken of Khloe during a private family gathering and posted to social media without permission by mistake," Tracy Romulus, chief marketing officer for KKW Brands, said in a statement sent to Page Six.
"Khloe looks beautiful but it is within the right of the copyright owner to not want an image not intended to be published taken down."
In a defiant public response to the leak, Khloe posted a lengthy statement and uploaded a naked video of herself.
In the statement, Khloe writes of having "struggled with body image her whole life" and argues that "you should have every right" to ask that unflattering photos of yourself are not shared.
"In truth, the pressure, constant ridicule and judgment my entire life to be perfect and to meet others' standards of how I should look has been too much to bear," she writes.
"For a decade now in photos, every single flaw and imperfection has been micro-analysed and made fun of to the smallest detail and I am reminded of them every day by the world."