Ant-Man hits theaters July 17, but Paul Rudd has already had some bonding time with The Avengers on the set of the next Marvel film, Captain America: Civil War, directed by Anthony and Joe Russo.

ET sat down with Ant-Man director Peyton Reed, who told us why he felt a little jealous when his lead character went to the Captain America set.

“When Paul went to shoot for a couple days on Civil War, I felt really envious,” said Reed. “I felt like my girlfriend had left me and gone off with the other guy.”

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Reed told us he met with the Russo brothers prior to filming, showing them plenty of footage from Ant-Man so they could familiarize themselves with the character.

“I felt very protective about the character,” said Reed, “I was like, ‘No he wouldn’t say that, he would say this!’ It was great. It was a great back and forth.”

But as they say, you want them to be happy, right?

“Paul called up and he was so excited,” said Reed. “He was like, ‘I mean, I know I'm a superhero, we did an entire movie together. But now I'm in this other movie, and I'm like talking to Captain America, it really is sinking in. I'm a part of the Marvel Universe!’ He was like a kid, it was amazing!”

And that’s not an exaggeration! Rudd shared that being on the set of Civil War was the moment when it really hit him.

“I went to the set of Captain America 3 and all of a sudden I’m standing next to some of the Avengers and I turned into, like a little kid!” said Rudd. “And they’re calling me by my character name!”