The 'Tonight Show' host also dishes on his daughters' personalities.
Everything Is Mama for Jimmy Fallon's two daughters, Winnie and Frances.
ET's Cameron Mathison sat down with the Tonight Show host in the Rainbow Room of 30 Rock in New York City last week, where he opened up about his second children's book, and what it's like as the odd man out in a house full of ladies.
"It's, 'Mama, read Dada,'" Fallon said of his kids' affection for their mother, even after his first children's book. "They didn't even want Dada to read Dada anymore. It's everything...If I'm doing it, they're not buying it. They just love Mama's voice. Mama's everything."
"The four-year-old listens to me, 'It's hot.' She goes, 'Hot, hot,'" he explained. "Then the baby, I go, 'Franny, stay here.' And I turn around and she has like two knives, I'm like, 'Where'd you get those knives?' 'I got them on Amazon...I got a Prime.'"
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!'"
"We just have a good time," Fallon added. "Who knows the adventures, what's going to happen?"
Everything Is Mama is available online and in bookstores now.