"The last time you gave me advice, it was great advice, and I now have two little girls. Any more parenting advice?" Fallon, 40, began. Since Garner was last on his show, the funnyman became a father for a second time. His first child, daughter Winnie Rose, became a big sister in December 2014 with the birth of younger daughter Frances Cole.
"So you have two... whoa," Garner, 42, said with wide eyes, mulling over the prospect of a parenting a 19-month-old girl and a 3-month-old infant. "Um, okay, so how are they now? How's your oldest so far?"
"She's good, she loves the little one, and like, kisses her every day," Fallon gushed of his daughters, whom he shares with his wife of seven years, Nancy Juvonen.
"She does?" Garner marveled. "Enjoy that. Take pictures, yes. No, I mean, they just have their, you know, they have their moments... You're driving to school and you kind of hear a yelp. You look in the rearview mirror and there's just like a pinch happening — a pinch for the ages."
"The hand is taken back so quickly, you're like, 'Why are you yelling?' Then the other one is like, 'Grrrr,'" Ben Affleck's wife added, making a pinching motion with her fingers and scrunching up her face. "Yeah, so the pinches."
The mother of three went on to add that the pinches aren't the only problem when it comes to raising little kids. The Danny Collins star and her husband of nearly 10 years now have three children together: daughter Violet, 9, daughter Seraphina, 6, and son Sam, 3.
"The other thing is that they can get clever," Garner dished. "They're all gonna go nuts when there's a new baby, right? One way or another, if it isn't now, it's going to be later. It's coming."
"We had one who wanted to still be the baby, but she never wanted to say, 'I want to still be the baby,'" the working mom spilled. "She wanted to be carried everywhere. What she was telling us was that she was a mermaid. She had a tail and she had flippers and she needed to be carried everywhere, and we bought it. Suddenly I'm lugging this huge kid around and I saw her smiling to herself, smirking... We would get to a staircase and she'd say, 'Oh my tail, what with my flippers, I can't make it up that staircase.'"
Doing an impression of her little girl as a mermaid, Garner added, "We're just totally going along with it... method, for sure. They're smarter than you are so just be ready for that."
Watch Garner and Fallon share parenting secrets in the video above!