ET

Aww Alert: Watch RDJ, Chris Hemsworth And Mark Ruffalo Share Dad Stories

As the Twitter kids would say... "Dad!"

Robert Downey Jr., Chris Hemsworth, and Mark Ruffalo all have something in common besides starring in the biggest superhero franchise on the planet: fatherhood. And for Hemsworth and Downey, the humans that they're fathering happen to be babies which, you know, doesn't always lend itself well to shooting "The Avengers" during all hours of the night.

That's why Downey seemed a bit incensed when he told ET the secret behind Hemsworth (and his wife, Elsa Pataky's) parenting success -- youth.

"Elsa's the greatest, but just seeing them come out to a brunch with a twin strapped on each of them, I just look and I think 'They're young. That's how they can do that,'" the 49-year-old joked.

Meanwhile, Hemsworth is just thrilled that his 2-year-old daughter can now say "papa," and Ruffalo is dealing with his teen son's major Hulk fandom.

"My son's hair is dyed green right now," Ruffalo explained. "His clothes are green, his hair is green. I'd like to think it was because of me."

Check out Entertainment Tonight for more adorable-ness, as well as some mild single-shading for poor, lonely cat lady Chris Evans.