"We shot 'Ant-Man,' but I was alone on that -- it was like working in a bubble, pretty much," he admitted on "The Graham Norton Show," "and then all of a sudden I'm standing around and seeing Robert Downey Jr. in the Iron Man suit, and seeing Chris Evans, and they're all there after I've seen the movies. I felt like I was 10 years old. It was crazy."
Rudd also confessed he got up close and personal with the Winter Soldier.
"I saw Sebastian Stan getting his arm -- the silver arm -- on, and ... it was weird, it was like I was watching somebody bathing," he said. "I'm not supposed to see this!" However, he quickly got over the momentary awkwardness, and ... walked over to feel the metal arm. Because, why not.
And then there was that time he held Captain America's shield while Evans ran to the restroom. Aw, we'll let Rudd tell that one. Watch the discussion below.
Directed by Joe and Anthony Russo, "Captain America: Civil War" opens May 6.