"I think my dream guest star right now is Shawn Mendes," she shared at the time. "I don't mean to be a mom crushing on him, but you know, we have young kids on the show, and I just can't stop listening to his album on repeat and I just think he would be perfect."
"Everybody was here… He's old enough to bring around," he told ET, adding that it was really his wife, Caitlin McHugh, who pushed him to introduce Billy, now nine months old, to everyone.
"I was sort of nervous about it because it was a big moment. She's like, 'It doesn't matter,'" he said. "I go, 'It does matter. This is an important moment. I've known these people for 30 years. I've talked about having kids and now I brought mine on.'"
It was a full-circle moment for Stamos, who watched his co-stars grow up on Full House.
"I got a little emotional because -- Bob [Saget] has come over and Dave [Coulier] and Lori [Loughlin] -- all of a sudden you see it, like, 'Oh my god. There's Candace and Jodie, and, you know, Stephanie and DJ and Kimmy Gibbler holding my little baby.' It got to me," he said. "I did have a flash of them [being] really little. I flashed to Jodie when she was running around here, like, 'How do you roast a turkey?' And I was like, 'Wow.' It was sweet."
Watch the video below for more on Billy's introduction to the cast: