John Stamos is one proud parent to his mini-me son Billy.
The "Fuller House" alum, 59, took to Instagram Tuesday to share a photo of his 4-year-old son’s milestone.
"One of us is starting his first day at school. And the other is doing everything in his power not to cry," Stamos wrote in the caption.
The father-son duo posed in front of a home in matching white button-down shirts, as his sweet son sported khaki shorts and leaned one arm on Stamos’ shoulder. Billy is seen holding a leaf and smiling for the camera.
JOHN STAMOS AND THE BEACH BOYS HONOR BOB SAGET AT LOS ANGELES CONCERT
Stamos shares Billy with wife Caitlin McHugh. The pair welcomed their boy in April 2018, two months after they tied the knot.
McHugh posted a similar snap of her holding Billy while petting a black dog. She’s also sporting a matching white button-down and green pants. Billy’s school backpack can also be seen in the background.
"Today was Billy’s first day at a new school!" McHugh, 36, wrote in her Instagram caption. "Nervousness and excitement all around."
In the beginning of the week, Stamos shared a precious photo of the family of three enjoying a Spider-Man-themed event.
CLICK HERE TO SIGN UP FOR THE ENTERTAINMENT NEWSLETTER
In the series of photos, the trio was seen posing at the "Glow Webs Glow" event at the Santa Monica Pier.
The family is all smiles, as Stamos is seen holding his son Billy in front of a large inflatable Spider-Man. Billy is also seen enjoying some fun activities at the event as he squirts a Spider-Man spray can.
CLICK HERE TO GET THE FOX NEWS APP
"Wonderful day at ‘Glow Webs Glow’ event celebrating Season 2 of #SpideyandhisAmazingFriends. I have the honor of playing one of his friends, Iron Man. @disneyjunior #marvel @disneyplus @caitlinskybound," Stamos captioned the photo of the happy family.