Kourtney Kardashian shows off her pert derriere in a racy thong bikini on a night swim

Kourtney Kardashian flaunted her sensational bikini body in a racy thong bikini to her more than 102 million Instagram followers on Wednesday night. 

While flashing her incredibly taut midriff and pert derrière, the 41-year-old reality star looked completely serene during her evening dip under the stars. 

As she floated in the water with her hands fully extended above her head, the self-professed ‘night swimmer’ gave fans a close-up of her famously gym-honed figure.  

Night swim: Kourtney Kardashian flaunted her sensational bikini body in a racy thong bikini to her more than 102 million Instagram followers on Wednesday night

The Poosh founder’s risqué slideshow included four shots, from nearly angle of her body, including a close-up of of her torso and one swimming away from the camera. 

Her extremely high-cut swimsuit left very little to the imagination, as it clung to the mother-of-three’s peachy posterior and displayed her every curve. 

Despite daring to show every inch of her lithe figure, Kardashian’s face was hidden under dark shadows or cropped out of every picture.   

Gym-honed figure: While flashing her incredibly taut midriff and pert derrière, the 41-year-old reality star looked completely serene during her evening dip under the stars

Gym-honed figure: While flashing her incredibly taut midriff and pert derrière, the 41-year-old reality star looked completely serene during her evening dip under the stars

Within the first two hours of posting, she garnered more than 500,000 likes and received thousands of complimentary comments from fans (seen over the weekend)

Within the first two hours of posting, she garnered more than 500,000 likes and received thousands of complimentary comments from fans (seen over the weekend)

Within the first two hours of posting, she garnered more than 500,000 likes and tons of complimentary comments from friends and fans.   

When asked where she purchased her two-piece, Kardashian revealed it was from Inamorata, which is Emily Ratajkowski’s swimwear line. 

Her black top string bikini top costs $75 and her matching bottoms are available at the same price.  

Famous curves: Her extremely high-cut, black swimsuit left very little to the imagination, as it clung to her peachy posterior and displayed the mother-of-three's every curve

Famous curves: Her extremely high-cut, black swimsuit left very little to the imagination, as it clung to her peachy posterior and displayed the mother-of-three’s every curve

She has previously shared her affinity for late night swims on social media, including posting a sweet video with her five-year-old son, Reign, in the pool over the summer.

In the footage, the beauty can be seen tenderly rubbing noses with her youngest child, who she shares with ex Scott Disick, under a crescent moon. 

As she stood in the water with her arms wrapped around her little boy, crickets chirped loudly in the background.  

Pert derrière: The Poosh founder's risqué slideshow included four shots, from nearly angle of her body, including a close-up of of her torso and one swimming away from the camera

Pert derrière: The Poosh founder’s risqué slideshow included four shots, from nearly angle of her body, including a close-up of of her torso and one swimming away from the camera

‘I have late night conversations with the moon. He tells me about the sun and I tell him about you,’ she captioned the recording and a series of striking snaps, which included multiple photos of glowing stars. 

Kardashian was using a quote from author, S. L. Gray, who penned the novel Skin, Bones, and Too Much Love, in 2018.

While nobody else was pictured with the mother son duo, one of her pals could be heard in the background saying, ‘Okay, now!’ 

'I have late night conversations with the moon. He tells me about the sun and I tell him about you,' she captioned a series of indistinct snaps, which included multiple photos of glowing stars (pictured in July with her five-year-old son, Reign)

‘I have late night conversations with the moon. He tells me about the sun and I tell him about you,’ she captioned a series of indistinct snaps, which included multiple photos of glowing stars (pictured in July with her five-year-old son, Reign)

She and her BFF Addison Rae recently fled Los Angeles to enjoy a weekend getaway to New York City. 

Kourtney and Addison originally met when Kardashian wanted to surprise her son Mason, 10, with the Tik Tok star, as a present.

After the initial meet up, the two ended up becoming close friends and Kourtney acts as a mentor to the budding star.

Mentor: Addison has revealed that Kourtney acts as somewhat of a mentor to her and that she can learn from Kourtney's experience

Mentor: Addison has revealed that Kourtney acts as somewhat of a mentor to her and that she can learn from Kourtney’s experience

The pair, though often receiving criticism for their age gap friendship, have spent almost every day together.

The two have traveled to Palm Springs, learned to surf together, share workouts sessions and frequently dine out at Nobu Malibu. 

Speaking about their friendship Addison said: ‘I think she has great energy as well and she has so much experience in her life that I can really just look at and kind of learn from.’