Celebrity Parents John Stamos Jokes 'Trust Fund' Were His Son Billy's First Words: 'He Has a Good Sense of Humor' John Stamos — who stars in The Little Mermaid Live!, airing Tuesday night — also opens up about a biting incident between his and Josh Peck's young sons By Jen Juneau Jen Juneau Twitter Jen Juneau is a digital news writer for PEOPLE since 2016. People Editorial Guidelines Published on November 5, 2019 01:40 PM Share Tweet Pin Email John Stamos‘ son William “Billy” Christopher is only 18 months old, but he’s already thinking about his financial future. In a chat with Extra on Monday at a red carpet event for The Little Mermaid Live!, the 56-year-old actor joked that his baby boy with wife Caitlin‘s first words were, “trust fund.” “He has a good sense of humor. That’s the milestone I like,” Stamos told the outlet, going on to imply that Billy isn’t as psyched about his dad’s role as Chef Louis in the upcoming live broadcast as he might be had Stamos been starring in a different Disney re-imagining. “I tried to get him to watch The Little Mermaid, the movie, and he just goes, ‘Coco, Coco, Coco.’ He loves Coco,” said the star. “That’s what he dressed up as for Halloween: Coco.” Never miss a story — sign up for PEOPLE’s free daily newsletter to stay up-to-date on the best of what PEOPLE has to offer, from juicy celebrity news to compelling human interest stories. John Stamos. Frank Micelotta/ABC See Auli’i Cravalho, Queen Latifah and More in First Look at The Little Mermaid Live! Event His resistance to going under the sea hasn’t stopped Billy from having a blast at his dad’s rehearsals for the show, though — even if much of his time has been spent trying to get the Fuller House actor’s attention. “I’m rehearsing my number, kinda for the first time on the stage — jumping on these tables, with knives and things — and all I could hear was ‘Dada! Daddy! Dada! Dada!’ ” he said in an interview with Entertainment Tonight from the same red carpet event. “I said, ‘Dada’s gonna fall off the table if you don’t shut up, kid,’ ” Stamos joked. John Stamos/Instagram RELATED VIDEO: ABC Announces The Little Mermaid Live! Event Starring Auli’i Cravalho, Queen Latifah and Shaggy In the meantime, Billy has been making some friends — and maybe even a few short-term enemies, much to his dad’s chagrin. “We were doing an episode of Fuller House, and I have a friend, Josh Peck, on [the episode],” Stamos told Extra. “His wife brings his son [Max Milo, 10 months] and my wife brings Billy, who’s never done a bad thing in his life.” “They were taking a picture and [Billy] leans over and bites Max [on the face]. … It was horrifying! It was the first time I was disappointed in my son. It was a weird feeling,” he added, joking, “Josh now owns my house in Hidden Hills and I’m looking for a condo in Encino.” The Wonderful World of Disney presents The Little Mermaid Live! airs Tuesday at 8 p.m. ET, live on ABC.