John Stamos Shares Sweet Picture of Himself Swimming With His Son

John Stamos is enjoying fatherhood, judging by the selfie he took with his infant son on Monday.

Stamos posted a picture on Instagram of himself and baby Billy in the pool. The little guy's head and face were covered by an over-sized sun hat, but he seemed to be having fun as he clung to his father's shoulder.

"Some days are just better than others," Stamos wrote in the caption.

Stamos welcomed his son back in April, along with his wife, Caitlin McHugh. They named him William Christopher Stamos, and they have quickly become some of the most beloved celebrity parents on Instagram.

Back in June, Stamos gave an interview with PEOPLE about how the arrival of baby Billy has changed his life. He was not shy about the process, admitting that it has been emotional and illuminating.

"It's been beautiful," he said. "Every second you pray that you can keep the kid alive. Every day is different, time has become very elusive, stuff just goes by so fast. It's just beautiful. I've cried most days; I just stare at him."

He also revealed that, as much as he and McHugh have documented Billy's development on social media, the baby actually does some of his best work whenever the cameras are off.

"He has my smirk, but he only goes into action when I turn off the camera!" he said. "I'll have to reverse that if he's going to be my son."

The actor told the interviewer that the birth of his son has reinvigorated his hope and faith in the world, and given him a more positive outlook on the future.

"We live in an anxiety-riddled, unsure, divisive time right now," he said bluntly. "I think most of us are searching, even subconsciously, to find what's missing from our lives: grace, charity, kindness, and peace, and family, and community and friendship."

Stamos, 55, has also leaned into his identity as a famous sitcom uncle, joking as if he and his character are similar, and Uncle Jesse from Full House is the one finally entering parenthood.

"From now on, the best part of me will always be my wife and my son," Stamos wrote beneath one photo. "Welcome Billy Stamos (named after my father)." Stamos added the hashtag, "not just an uncle anymore" to the picture.

Stamos is expected to return to Netflix's Fuller House for season 4 sometime soon, though an official release date has yet to be confirmed.