Kourtney — who gave birth to son Rocky roughly five and a half months ago — didn’t seem to mind and responded underneath a comment which read, ‘Now you know she’s not going to like this photo… lol it’s her bday Kim… lol.’

The mom-of-four wrote back, ‘I LOVE this photo! It is me and my sisters having the best time on a trip with our kids… and the memories to last forever! And I LOVE this body that gave me my 3 big babies and my little baby boy.’

Kim Kardashian, 43, took to Instagram on Thursday to mark her sister Kourtney’s 45h birthday with a bikini snap of her with Kourtney and younger sister Khloe, 39, that left fans divided

Kim penned a sweet caption to her sister underneath the snap, writing, ‘Happy Birthday Queen.’

‘There’s no one on this planet that I have spent more time with and have all of the same memories with growing up than you and I cherish them all.

She went on, ‘Sharing a room and friends and cars and our lives together for four decades has been the most magical journey to have you by my side.’

‘I love you and I can’t wait for another 45 years together! I will especially cherish this last sister trip where all of our kids had dance parties til they passed out, the way we all did growing up!’

‘Celebrating you today and grateful to you forever for always giving the best advice a sister could possibly give!’

Kourtney — who once called Kim a ‘witch’ — was touched by the tribute, writing, ‘This caption [heart emoji] I love you sooooo and so grateful for all of the incredible memories we have together… when I think it, it’s like a movie plays in my head of all of them! So blessed!’

Her husband Travis Barker, 48, also left a heart emoji on the post.

After Kim made her tribute, a number of fan comments poured in, questioning the choice of the ‘shady’ photo. ‘Well this was intentional,’ one person wrote.

Kim penned a sweet caption to her sister, writing, ‘Happy Birthday Queen’, but the snap caused a stir, with many claiming Kim intentionally picked a photo in which she looked the best

Kourtney herself didn’t seem to mind and wrote: ‘I LOVE this photo!… And I LOVE this body that gave me my 3 big babies and my little baby boy’

After Kim made her tribute, a number of fan comments poured in, questioning the choice of the photo. ‘Well this was intentional,’ one person wrote

‘Shady af,’ another comment read

However many others praised Kourtney for having the ‘most natural’ looking body out of all her sisters

‘Seems like Kourtney is the only one with a REAL belly button,’ someone else added

‘Spot the tummy tuck X2 vs the au natural,’ yet another commentator added

The comments continued with one fan writing, ‘Kourt looks so fire postpartum!!!’

‘Idk what y’all talking about it, Kourtney’s tummy is the most natural looking out of all of them’

Many said they ‘prefer’ how Kourtney looks

‘I think Kourtney look absolutely gorgeous yay for her looking real!!’

‘Kourtney’s mom bod is [fire emojis]’

Another fan took a swipe at Kim, who once said Kourtney was the ‘least interesting to look at’ and wrote, ‘Kourtney is the MOST interesting to look at! Pure beauty!’

Kim and Kourtney — who’ve had a rocky relationship in the past — seem to be on good terms at the moment, after recently enjoying a family holiday together; seen in 2018

However many others praised Kourtney for having the ‘most natural’ looking body out of all her sisters.

‘Jokes on Kim cause I actually think Kourtney looks the best here… most natural,’ one fan wrote. ‘Seems like Kourtney is the only one with a REAL belly button,’ someone else added.

‘Spot the tummy tuck X2 vs the au natural,’ yet another commentator added.

The comments continued with one fan writing, ‘Kourt looks so fire postpartum!!!’

‘Idk what y’all talking about it, Kourtney’s tummy is the most natural looking out of all of them.’

‘I think Kourtney look absolutely gorgeous yay for her looking real!!’

‘Kourtney’s mom bod is [fire emojis].’

Another fan took a swipe at Kim, who once said Kourtney was the ‘least interesting to look at’ and wrote, ‘Kourtney is the MOST interesting to look at! Pure beauty!’

Kim and Kourtney — who’ve had a rocky relationship in the past and once got into a physical altercation on their reality TV show The Kardashians —  seem to be on good terms at the moment, after recently enjoying a family holiday together.

Aside from Kim’s tribute, Kourtney was also showered in love by her other family members.

Khloe also shared a bikini snap of her and Kourtney, writing: ‘Happy birthday to my Jane @kourtneykardash, my sugarplum fairy, my teeny tiny box of treats you are. Towanda for life! You deserve every ounce of happiness, love and blessings that you receive!’

Kourtney’s husband Travis Barker shared a photo of her on the toilet. ‘Happy Birthday to my beautiful wife, soulmate and best friend forever. I love you, I love our life together’

Kourtney gave birth to their son Rocky roughly five and a half months ago. She also shares Mason, 14, Penelope, 11, and Reign, 10, with ex-partner Scott Disick, 40

Khloe also shared a bikini snap of her and Kourtney, writing: ‘Happy birthday to my Jane @kourtneykardash, my sugarplum fairy, my teeny tiny box of treats you are. Towanda for life! You deserve every ounce of happiness, love and blessings that you receive!’

Her mother Kris Jenner was the first to post. She called the POOSH founder her ‘first born baby doll’ as she shared throwback photos of the beauty.

Jenner also said that Kourtney was a ‘beautiful and amazing daughter.’

Meanwhile her husband Travis shared a photo of her on the toilet.

‘Happy Birthday to my beautiful wife, soulmate and best friend forever. I love you, I love our life together. Thank you for being the most amazing wife a person could ask for. Here’s to many more years of adventures together ❤️‍,’ he shared.

Kourtney is now a mother of four: she has Rocky with rock star Travis, as well as Mason, 14, Penelope, 11, and Reign, 10, with ex-partner Scott Disick, 40.