"You know, life goes on. We can't sit around and wait for Chris Evans," Mark Ruffalo says of the hurt feelings he and Chris Hemsworth felt over being left out of Captain America: Civil War.

"We have to get on with our lives. It's bittersweet, but he has to deal with it. He went off and made his own little Marvel indie movie with all the other little actors, and what are we gonna do? Just sit there and wait it out? Like, wait for Chris [Evans] and the rest of 'em to come back around to Chris and Mark? No way, man. We're moving on! We got our own thing happening," he breaks into a dramatic moan. "We don't need you guys. We never liked you anyway!"

In turn, Hemworth's God of Thunder and Ruffalo's Hulk went on their own grand adventure in Thor: Ragnarok, but soon enough everyone will need everyone when Earth faces its greatest threat in Avengers: Infinity War, out April 27. Which means that Bruce Banner will be reunited, at last, with his fellow Avengers...as well as the Guardians of the Galaxy, Black Panther, Spider-Man, Doctor Strange and more, in Marvel's biggest team-up yet.

"No wonder I only have, like, four lines in the whole movie," Ruffalo joked to ET's Brooke Anderson on the set of Infinity War. "We had to share it with all these other people."

Of the old guard, it will be most interesting to see what happens when Banner and Black Widow come together again, having become somewhat star-crossed in Age of Ultron, before Hulk stole a quinjet and flew off into the unknown. "That doesn't go away. Those things never do," Ruffalo teased. "It's requited or unrequited, but it never goes away. And so you'll see more of that."

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Then there are all the new recruits. "Chadwick [Boseman] and Danai [Gurira], those are the only ones I've worked with so far," he added of the Black Panther actors. At the time of ET's visit, the Atlanta, Georgia, set had been transformed into the Afrofuturistic nation of Wakanda for a pivotal set piece in the film. "It's such a different universe. I think the core value of this film is its diversity and that they're all stronger because of that diversity."

"I always think of these movies as kind of like modern mythology. They reflect the moment we're in culturally and the ideal of that moment, or where we want to be coming out of that moment," Ruffalo continued, revealing that while Civil War was about division, the theme of Infinity War is about coming together. "That's why it transcends all kinds of political bounds, racial bounds. People love these movies because they're the stories of gods and monsters. It tells us about ourselves, and it tells us about how we behave in this new world: What's right, what's moral, what the struggles are."

An Avengers movie wouldn't be an Avengers movie if we didn't also see Banner's struggles with going green, which became far more complicated after the events of Ragnarok. "Because of the physics of this planet, Banner and Hulk separate out from each other," Ruffalo recapped of Hulk's time spent as an intergalactic gladiator on Sakaar. "So, you have a Hulk that doesn't only exist when he's angry, but basically is living...It's all very comic book-y."

"You start to get to explore Hulk outside of just being angry," he added of the Hulk's continued evolution over Infinity War and an untitled fourth Avengers due out next year. "And we all love the Hulk because he's always angry and we love that relationship between him and Banner. But there's also something exciting about getting to know Hulk outside of that. And he's very funny! He's very childlike, of course. He's gone from a raging 2-year-old to, like, a 6-year-old."

"His progression through all these movies is he's just getting more and more mature," Ruffalo weighed in. In another decade, then, Hulk might be a teenager. "Yeah," the actor deadpanned. "And someone else will be playing him."

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