SAN DIEGO — Actor Chris Evans recently filmed a kiss with co-star Scarlett Johansson on the set of "Captain America: The Winter Soldier" — and says it was a little like kissing his sister.

The two stars reprise their roles as Captain America and Black Widow in the sequel, currently in production and set for release next April.

Evans said in an interview Saturday at Comic-Con to promote the new film that he's known Johansson for more than a decade since they co-starred in the 2002 film "Perfect Score."

"She was a kid. She was like 16 or 17 years old," Evans said. "I've known her for over a decade now, so she's like my sister. We have this little kiss scene. It will all make sense in the movie."

The 32-year-old Evans didn't want to underplay the kiss — "It's still a big deal, let's be real" — but as one of film's hunkiest leading men and the boyfriend of actress Minka Kelly, kissing beautiful women is a way of life. He says he and Kelly, the 33-year-old "Friday Night Lights" star, have no problem with jealously over their on-screen relationships.

"My girl's an actor, too, so you kind of understand that," Evans said. "We're like, 'Hey, it's Ok. It's what we do, what we do, what we do."