"Pinky swear?!" Kardashian captioned the upload, as she struck numerous alluring poses in a pink triangle bikini from her brand SKIMS.
The reality star flaunted her toned tummy and hourglass figure, while styling her long brunette tresses down in a natural, loosely waved hairdo.
While the post generated nearly 2 million "likes," most people in the comments section angrily mentioned the potential editing of Kardashian’s body.
"Looking completely different in every single pic 😂," one hater wrote, accusing the socialite of altering her images.
Others pointed out one of Kardashian's literal cosmetic enhancements: lip filler.
"Them lip injections sites obvious," a critic commented, as Kardashian slightly stuck her tongue out between her lips in one of the pictures.
"Bee sting top lip," another user chirped, as someone noted, "top lips are almost bigger than the ones below."
The mom-of-four didn't let the haters bring her down, and later proved she works hard for her fit physique by hitting the gym for a morning workout on Wednesday, June 14.
"A little workout energy this morning. I don’t post my daily workouts but we’ve been putting in work and it feels really good," the 42-year-old shared with her 359 million followers.
"This is harder than it looks!" Kardashian added alongside a video of her doing a weighted ab exercise.
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As the aspiring lawyer focuses on her fitness journey, her attention has also seemed to turn back to the romantic aspect of her life, with rumors circulating about a mystery man she referred to as "Fred" during a recent episode of The Kardashians.
During the show, Kardashian revealed she and her new beau like to meet up at her favorite New York City restaurant, which is equipped with a private room downstairs.