'Captain America' Star Chris Evans Jokes With Young Fan About Arm Wrestling Dad

— -- In "Captain America: Civil War," Chris Evans takes up the shield for the fifth time.

Evans celebrated "Captain America Day" on “Good Morning America” and revealed what it feels like to fight against a friend.

“It’s the first time he doesn’t know what’s quite right or wrong,” Evans told Amy Robach. “He’s a very binary thinker and I think in the previous incarnations it’s clear to understand…aliens invading are bad -- this is the first time he’s not quite sure which side of the fence to fall on.”

In the film, Captain America dukes it out with Iron Man (Robert Downey Jr.), and just like the fans, the rest of the Avengers have to choose sides.

“Seeing friends fight friends is a little more dynamic than seeing a friend fight an enemy,” Evans said.

In Times Square this morning, Evans was interviewed by pint-sized fans that proudly wore their Captain America gear in support of their favorite superhero.

“My dad’s on ‘Team Iron Man’ and I’m on ‘Team Cap.’ What do you think I can do to make him be on ‘Team Cap?’” asked little Camilla.

Evans responded: “Your dad’s on ‘Team Iron Man?’ Is he a big man? Because I would say I’ll arm wrestle him – and then we’ll squash it once and for all, but if he’s like 6-foot plus I’d say maybe let’s talk it out.”

"Captain America: Civil War" opens nationwide tomorrow.