The Keeping Up With The Kardashians star, 35, gave her 14 million Twitter fans plenty to coo about on Thursday night (2 April) when she posted a photograph of her third child, born in December.
In the snap, baby Reign is staring up at the camera with big brown eyes and the hint of a smile on his lips - awwww!
Dressed in a white babygro, the youngest member of the Kardashian dynasty has his teeny fists clenched and has very little hair on his young head!
Alongside the heart-melting snap, proud mum Kourtney wrote: "My little turtle dove angel baby boy Reign Aston Disick."
Previously, Kourtney has only shared a snap of Reign's tiny little hand in hers and his booted feet.
Fans were quick to tell the mum-of-three what they thought of her youngest child.
The words "cute" and "adorable" crop up a lot unsurprisingly, while one remarks on Reign's resemblance to his older brother, saying: "Aww, he looks like Mason."
Smitten grandma Kris Jenner also shared the cute photo on social media, writing: "Meet my beautiful grandson!! #blessed #oneofthelovesofmylife."
Auntie Kim wrote: "My RAD little nephew...Reign Aston Disick."
Reign is Kourtney's third child with partner Scott Disick. They also have Mason, five, and Penelope, two.
The tot was born on Sunday 14 December 2014 - which, by happy coincidence, happens to be Mason's birthday, too.
Reign has yet to make an appearance on the family's reality TV show.
Kourtney has made no secret of the fact she is attempting to regain her figure after giving birth, and recently told fans she was slowly reaching her goal.
Meanwhile, dad Scott Disick checked into rehab last month.
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