Chrissy Teigen and husband John Legend have their hands full with their four children.

The model and television personality gave birth to their second daughter Esti in January, and then came son Wren, via surrogate in June.

Now just one month into their lives as a family of six, which includes daughter Luna, seven, and son Miles, five, the Cravings cookbook author had a major breakthrough with little Wren on Sunday and couldn’t wait to share it with the world.

Taking to Instagram, the proud mama posted a video of Wren caught on camera the moment he flashed a big beaming smile.

‘FINALLLLLLYYYYY! A smile,’ Teigen shared in the caption, which sounds as if this may be the first time she was able to get her boy to crack a smile.

Monumental moment: The mother of four was cradling one-month-old Wren in her arms when she got a family member to start filiming her
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Beaming: While filming Teigen with Wren in her arms, he flashed a smile, which sounded as if it may be his first glowing grin
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Cherished moment: Chrissy Teigen, 37, shared a video on her Instagram page showing her newborn son, Wren, smiling on camera

The short 10-second video begins with Teigen cradling Wren in her arms while sitting on a couch in the living room of their Beverly Hills mansion.

‘Hey look. Oh my God. Oh my God,’ the former Sports Illustrated Swimsuit Issue model can be heard excitedly announcing when she notices her son Wren has begun to crack a smile.

‘You get it?’ the proud mother of three asks the person who’s been given the task of filming mother and son in this milestone moment.

‘Oh my gosh, it’s so big,’ she blurts out even louder, in a reference to his big beaming grin.

In the clip, the former Lip Sync Battle star can be seen staring down at her boy, who’s dressed in a white-patterned onesie.

Initially, Wren just stares back at his mom with a relaxed look on his face, but just a few seconds in he starts to show off his infectious grin.

And the little guy hold that sweet smile for more than a few seconds, all to his mother’s delight.

Adorable: The short 10-second video begins with Teigen cradling Wren in her arms while sitting on a couch in the living room of their Beverly Hills mansion
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Adorable: The short 10-second video begins with Teigen cradling Wren in her arms while sitting on a couch in the living room of their Beverly Hills mansion

Glowing: The one-month-old boy starts to smile for the camera
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Infectious: As the mother of four gets more excited, Wren's smile gets even bigger
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Excited: ‘Hey look. Oh my God. Oh my God,’ the former Sports Illustrated Swimsuit Issue model can be heard excitedly announcing when she notices Wren has begun to crack a smile

Lighting up mom's life: Teigen wrote in the caption,' FINALLLLLYYYYY! A smile, which sounds as if this may be the first of his short little life
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Lighting up mom’s life: Teigen wrote in the caption,’ FINALLLLLYYYYY! A smile, which sounds as if this may be the first of his short little life

Growing family: Teigen and Legend welcomed their second son on June 19 after the family found the 'most incredible, loving, compassionate' surrogate
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Growing family: Teigen and Legend welcomed their second son on June 19 after the family found the ‘most incredible, loving, compassionate’ surrogate

The couple welcomed their second son on June 19 after the family found the ‘most incredible, loving, compassionate’ surrogate, they had previously announced on social media.

They had decided to go that route after suffering a heartbreaking pregnancy loss in 2020.

But Teigen ended up getting pregnant last year with baby Esti, and then gave birth to the adorable little girl on January 13.

Family of six: Last week, Teigen posed for a photo or two with all of her babies which includes sons Wren, one month, and Miles, five, and daughters Esti, six months, and Luna, seven
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Powerful statement: Teigen confessed she in the line of people who choose ‘pills and surgery’ over making ‘lifestyle changes’ to help remedy certain health ailments

Just hours before her milestone moment with her newborn, Teigen shared a funny meme about decisions people make between ‘choosing pills and surgery’ over ‘lifestyle changes’.

From the looks of the hilarious picture, most if not nearly all people are of the mind to choose pills and surgery as remedy for health ailments as opposed to making a change in lifestyle for things like high blood pressure and high cholesterol.

Showing her sense of humor and honesty, Teigen inserted her image into the long line on the left, which are the people who pick what appears to be the easier path of medication and operations, which is not always the more healthier choice between the two.