While Fallon keeps his eye on Franny, he says both his daughters already love performing. "They watch Daddy. They've seen me dress as a 15-year-old girl. They're kind of like, 'Yeah, that's what Dad does,'" he explained. "They just love to be silly and laughing. They're very happy kids."
The former Saturday Night Live star's kids also get a lot of sleep -- while their dad hangs out with pals like Justin Timberlake. "The book is short enough, so you can read the book and get the hell out of the bedroom," he joked, before dishing on his bromance with the singer.
"He's just a good guy, very creative," he shared. "I got a tandem bike for my birthday. Justin comes over and goes, 'Let's go ride it.' I go, 'Want to go bro biking?' And he's like, 'Bro biking! Let's do it!'"