The knickers, which are priced at an affordable £15, come with a built-in padding to give your bum a little extra oomph.
So, if you feel like your booty could do with a lift and sculpt, M&S' will come to rescue.
Since their launch earlier this year, the shorts have already gone viral on social media and in the world of fashion - and even star Lorraine Kelly couldn't resist trying them on live TV.
One of those who also recently got a pair of the garment was shopper and style enthusiast Ali Bailey, from Manchester, the UK.
The trendy fashionista said that she was looking for nude lingerie when she spotted the bum-enhancing shorts and initially thought that was a bra.
But upon further inspection, she revealed in a video posted on TikTok, Ali realised that these were bottoms to make your booty look more plump.
Going to run to the nearest Marks and get a pair
ShopperTikTok
Although the blonde beauty wasn't self-conscious about her buttocks, she was aware that there was a demand of bum-boosting gear, especially amongst her friends.
''I'm okay with my bottom, it's not something I've ever wanted to make, like, any bigger.
''I have friends who are like 'Oh, I wish I had more in my bottom area', so I get it - it's a thing.
''M&S wouldn't have come up with it if it wasn't a thing,'' Ali noted in .
The must-have shorts of the season that suit everybody – and how you can wear them for all occasions
As reported by the shopper, there's clearly been a huge demand for the garment, as just two days later all but a few pairs in XL and Medium were sold out.
Before trying on the shorts, which she had purchased in black, Ali gave the viewers a quick look of her body, showing what her bum looked like from the side.
Once the padded knickers were on, Ali adjusted them to ensure a perfect fit and was in hysterics when she glanced at the new fake booty, which was visibly perkier and rounder.
''Wow, they definitely work,'' the M&S fan couldn't get over the instant results.
Although getting jeans on was a bit of a struggle, Ali was amazed at how good her bum was now looking - in fact, she was so chuffed with the bargain, she said it gave the illusion she's ''been squatting for life''.
The delighted customer went on in the caption: ''If you’re wanting to lift, enhance & increase the look of your bum, these definitely do the trick!
Why Everyone Is Loving M&S
Deputy Fashion Editor Abby McHale revealed to Fabulous why M&S is the shop of the moment. She explained:
“M&S has really pulled it out of the bag this season, there is so much good product to be excited about.
“A brand once known for its ‘frumpy fashion’ that notion is long gone with it now being one of the leading high street stores for womenswear.
“Its handbag range in particular is super strong with them selling 170% vs plan, with lots more designer dupes for just a fraction of the price.
“The brand is now also the #1 for style perceptions, compared to the #3 spot it had last year, this comes from a really strong design team focused on modernising the brand, not only taking into consideration how the pieces look, but how easy they are to wear also.
“Price is also a big factor with you being able to get many good quality pieces all for under £30.
“After having a sneak peak of the upcoming collection there are so many more amazing pieces that are dropping over the next few months to keep your eyes on.
“Think leopard print dresses, colourful co-ords, embroidered boho jackets, plus lots of swimwear and amazing accessories, as well as great wardrobe staples that will last year on year.”
''They’re £15 available in nude it black, sizes S - XL. I’ve got the medium on for reference.''
Fellow style lovers flocked to comments where they, just like Ali, was stunned by the transformation.
''Looks so good,'' wrote one TikTok user.
Someone else couldn't wait to get their hands on the garment, writing: ''Going to run to the nearest Marks and get a pair!''
''I deffo need some,'' a third chimed in.
Chatting about the Kim K. effect shorts, Soozie Hebkinson, head of lingerie design at M&S, said: "We've been doing for bums what we've done for boobs for years."
''We've had requests from both UK and international customers,'' said Soozie, who calls the pants the ''BBS'' – bum-boosting shorts.
Soozie added: ''We're going out more and it's making us think about lingerie solutions to help us get dressed up again.