The 65-year-old actor appears on Friday's episode of The Talk with his daughter, Ella Bleu, and discusses how he can't contain his pride while he watches the 19-year-old actress work.
"I am ridiculous. I'm behind the camera mouthing every word she says, doing her moves," John admits. "My wife, Kelly [Preston], gets hysterical watching me watch her, because I just want it to go great."
The father-daughter duo recently co-starred in The Poison Rose, and John recalls the tough task Ella was given on her very first day.
"Poor Ella, she hadn't acted since the film with Robin [Williams], and they gave her the most complicated scene," Travolta says, referencing the 2009 flick, Old Dogs. "Four in the morning, she had to cry, hold a gun, consider all sorts of things, and she nailed it. And the crew gave her a big applause because you wouldn't give it to anyone to do at that time. But I said, 'Well, she's on her own. She's got to deliver.' And she did."
While some might be extra nervous with their famous parent on set, for Ella it was actually a relief.
"It actually helped so much knowing that he was there," she says. "... He would come up in between scenes... and then I would know that I had him behind the monitor, just watching, making sure it was good."
In addition to being a stage dad, John also makes it his mission to stay hip, even beating his kids -- he and Kelly also share Benjamin, 8, and their late son, Jett -- to some of the hippest trends.
"I mean at home, we will put on music and dance. At New Year's, for hours, we were all dancing, and just to all sorts of music. So, it's really fun," Ella says of watching her dad dance. "He's more teaching us the moves. When, like, the floss first came out, he was like, 'Look at this video.' And we were like, 'Oh wow.' So he sort of introduced us to that. So he's on top of everything more than we are."
"You have to stay current," John teases.
While his dance moves don't embarrass Ella, there was a different mortifying moment she'd like to forget, one that she shared during their appearance on Jimmy Kimmel Live earlier this week.
"Taylor Lautner was coming over to the house and I loved him. Team Jacob for sure," Ella quipped of the actor's Twilight character. "And my friends and I were looking up pictures of him, just sort of, like, researching him. Like, 'Oh my gosh, he's coming!'"
"And then Taylor gets there and his family as well, so I was researching about them too, just to learn," she continued telling the show's guest host, Lena Waithe. "Then, the first thing [my dad] says to them is, 'Oh, Ella was just looking you guys up on the internet."
"A father's point of view is, you know, everybody loves Taylor Lautner, wouldn't he be flattered that Ella's looking him up?" John said in defense of himself.
Despite her embarrassment, Taylor laughed off the exchange as she cringed awkwardly. "He was like, 'Oh [laughs], that's so nice,'" Ella recalled. "And I was, like, [grimacing] with my face bright red probably."
Watch the video below for more on the father-daughter pair.