When Princess Charlotte was spotted cheekily poking her tongue out during a recent public engagement in the UK, it seemed the entire world got a laugh out of it - and that includes her mum Duchess Catherine.
Indeed the golden moment was captured for all to see when photographers snapped pictures of the tricksy Princess making the gesture, which was later revealed to be directed towards her grandfather, Michael Middleton - a sweet insight into their playful relationship.
But ultimately, it was Kate's hilarious reaction that really put the cherry on top of the royal pie - because the mum-of-three took the whole moment, which could have been seen as a little er... unpoised, entirely in her stride.
Attending the Kings Cup Regatta in Cowes, England on August 8, the Cambridge family (apart from little Louis) were out in full force.
Both Wills and Kate got right into the thick of things by competing at the event themselves, which was held in support of the charities they work with in their roles as members of the royal family.
George and Charlotte were also treated to a sail extravaganza, being spotted on a spectator's boat with their grandparents Carole and Michael Middleton.
And after all the race fan-fare was complete, fans were delighted when Charlotte was reunited with her mum, where the now-infamous tongue-sticking-out moment occurred.
Kate's reaction to the aforementioned moment (which was to roar with laughter), has been praised by royal watchers, who were thrilled to see Kate looking more relaxed and confident than ever as a royal.
And her technique of seeing the lighter side of things when it came to her daughter's cheeky moment has certainly not gone unnoticed.
In fact, as pointed out in a report by Hello!, there are some striking similarities between Kate's reaction to Charlotte and the way Princess Diana brought up her own children.
The proof is in the pictures - as the publication pointed out, an image of Princess Diana in 1993 visiting Thorpe Park, one of the biggest theme parks in the UK, has revealed the two women are more alike than we thought.
In the glorious image taken in 1993, Princess Diana is seen roaring with laughter alongside her two boys after being soaked in water on a ride.
It's a sweet and telling piece of evidence to prove the late Princess of Wales never lost her joyful nature, even in the face of, er... tricky circumstances.
And the same could certainly be said for Kate, who had the same gleeful reaction to her daughter this month.
WATCH: Video from the Kings Cup that proves Kate Middleton and Prince William are more in love than ever. Story continues after video...
It is widely known that Princess Diana absolutely doted over her two sons Prince Harry and William, going to great lengths to ensure they could enjoy moments other children their age could, without the pressure of constant media attention.
In fact, even the visit to Thorpe Park proved Diana's drive to ensure the boys could still lead a normal life, insisting that they queue for the rides just like members of the public, without any special treatment.
It's clear from this that both Diana and Kate have like-minded parenting methods - Kate has also been spotted sharing some sweet moments with her children as though no press photographers exist.
In July, Kate was snapped attending a polo match with her three young children to watch Prince William compete.
In some of the candid pictures, Kate is seen playing with her youngest child Louis, pulling funny faces and providing us a glimpse into her casual and joyful parenting methods.
Suffice to say we're cheering for both royal mums for choosing to raise their children as normally as possible, despite their unique circumstances.