John Stamos' Son Is All Grown Up And Making Us Say Have Mercy

Uncle Jesse junior.

Johns Stamos recently shared a series of photos to Instagram from a trip to NYC, which included several father-son snaps with his only child, Billy. In the first photo, the 4-year-old—who he shares with wife Caitlin McHugh—looks more grown up than ever, as he posed alongside his dad while bundled up in a plaid puffer coat, with his wavy light brown hair under a sage green knit beanie.

In another pic, Billy rocks a handsome red velvet suit while on stage with John at the legendary Carnegie Hall where the Full House alum performed as part of the 2022 holiday tour dubbed "Tis the Season with The Beach Boys featuring The Holiday Vibrations Orchestra" on Dec. 5.

John captioned the Dec. 12 post, "NYCdump pt. 1."

In the comments, fans were quick to gush over Billy, with one writing, "What a sweet boy, a total daddy look a like," while another wrote, "Beautiful boy. He has your hair."

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John and Caitlin welcomed their baby boy—named after the actor's late father—in April 2018, two months after their wedding. "From now on the best part of me will always be my wife and my son," John wrote on Instagram when introducing his baby boy to the world, also adding the hashtags "#notjustanuncleanymore #overjoyed."

Despite their online attention, John recently joked that Billy "hasn't really" fully grasped how "cool" his dad is. However, the 59-year-old said that he and Caitlin, 36, have made a point in keeping their son grounded.

"I just have to lay the foundation of being loving and kind, and teach him to be that," John told E! News in October. "I think we're pretty good examples, my wife and I."

He continued, "The hard thing is he lives a pretty privileged life. [My wife's] great, she takes him down to feed the homeless in Orange County and we take him on stuff like that. We try to show him it's about service and giving back."