John Stamos Sends Message to ‘Full House’ Co-Star Ashley Olsen on Birth of Baby Boy

John Stamos is congratulating Full House co-star Ashley Olsen on the birth of her son. After the fashion designer, 37, and husband Louis Eisner, 34, welcomed their first child, a son named Otto, Stamos took to Instagram with a tribute to Ashley and her twin sister Mary-Kate Olsen that culminated with sweet words about the former’s motherhood journey.

“Watching Mary-Kate and Ashley grow into the incredibly bright and remarkable women they are today has been one of the greatest joys of my life,” wrote Stamos, 60, alongside a compilation of throwback moments with the Olsen twins on the Full House set and beyond during their childhood. Also included were moments spent with the Olsens together later on in their adulthood. “If you would have told me those blue-eyed babies I met on set nearly 40 years ago would still be in my life at 60 years old, I wouldn’t have believed you,” Stamos continued. “I am blessed.” The actor concluded his post, “Congratulations to Ashley and her husband, Louis, who welcomed their baby boy last week.”

Over Stamos’ post, he included a voiceover from his new autobiography, If You Would Have Told Me: A Memoir, to be released Oct. 24. In the preview, Stamos recalled Mary-Kate and Ashley being cast as Michelle Tanner on Full House as he reflected on their relationship over the years. “The last casting call is for Danny’s little daughter,” said Stamos, who played Michelle’s Uncle Jesse on the ’90s sitcom. “Two adorable munchkins, Mary-Kate and Ashley Olsen, are cast in the role of Michelle. They have big blue eyes wide with wonder.”

Stamos continued, “Right away I know the relationship between Jesse and Michelle is an important one, but as the show develops the connection grows. I’m young but I really want kids someday and these lovely little girls so bouncy and bright represent the best versions of future dreams. They allow me to consider fatherhood like a benched baseball catcher in a dugout, watching from afar but not having to catch any curve balls.”

From there, he continued that the twins became the kind of kids he hoped to have one day. “I take them to Disneyland, I adore them, giving them kisses on top of their head, buy them a few crappy souvenirs and then hand them back to their parents to do the hard work,” he said. “The little kids that were supposed to be background noise grow up to become the kind of humans I hope to have one day. They are precious, delightful and bright. I adore them.”