John Stamos celebrates Father's Day by sharing first full picture of baby son

Stamos, who has been very private about his son since his birth in April, finally shared a full picture of the infant for Father's Day.

One is never too old to be a father and John Stamos, who welcomed his first child with wife Caitlin McHugh this past April, is further proof for the same. 54 years old, Stamos celebrated his first-ever Father's Day as a dad this past Sunday and marked the occasion by sharing a rare snap of his son on his Instagram page.

Stamos has been scrupulous about avoiding posting pictures of his infant son, Billy, but decided that Father's Day would a good time for the world to have a proper look at him. Accompanying the post was a heartfelt caption where the actor stressed the significance of the event to him and what it now meant to him as a new father.

Stamos shared some pictures of his son (Source: Instagram)

"My first Father’s Day means that I don’t have to hand a kid back to the parents when someone yells cut," he wrote, adding: "It means when people ask me if I'm a father, I don't have to use the goofy line, 'No, but I play one on TV.'"

He continued: "My first Father’s Day means that from this day forward— I will start to look my age (and older) Most importantly, it means that for the rest of my life, I’ll always be known as someone’s dad. And that’s all I ever wanted."

A post prior to that one similarly had Stamos caressing his son, giving him a light peck on the forehead. The caption felt equally poignant. He wrote: "Look at my son, pride is not the word I’m looking for, there is so much more inside me now. When you smile, I fall apart."

The actor, musician, producer, and singer, best-known for his roles as Blackie Parrish on ABC's 'General Hospital' and Jesse Katspolis in 'Full House,' announced his engagement to model and actress Caitlin McHugh this past October. The couple had dated for a year prior, and in December announced they were expecting their first child together. They tied the knot in February this year.

McHugh similarly celebrated Father's Day with a passionate and full-hearted message directed at her husband that she posted on her Instagram page. She wrote: "Happy 1st Father’s Day to the best new daddy! I knew you’d be a great father, but you’ve exceeded expectations. You change diapers! Lol, and so much more, of course. We love you most."

She has, in the past, also expressed her desire to have more children with Stamos, telling Entertainment Tonight that she would expand the family 'as soon as I can!' and that Billy needs siblings to keep him grounded. She joked: "If he's the only one, he'll get way too much love because there hasn't been a child on either side of our family in quite some time."