Sigourney Weaver has addressed "legitimate" concerns over her kissing scene with Jack Champion

However, Sigourney has revealed they actually shot the kiss separately.

She told The Hollywood Reporter: "That scene where I say, 'You're perfect just as you are', we had to be very delicate about that scene because it included a kiss. Obviously I wasn't going to kiss Jack, who was 14 or 15, in real life.

"We asked Jack to pick someone I could kiss and he did. Then I imagine when I wasn't there, they picked someone appropriate for Jack.

"That concern about all of that, which is quite legitimate, was going on.

"And I'm glad the scene survived, because when I saw it, I believed it. It's so genuine between the two of them and any concern about Jack's real age and my real age, I think there's no room for it there."

Sigourney clarified there was "only that one moment" that she and Jack filmed separately and she loved how "mismatched" they appeared together.

She said: "It was only that one moment.

"It was like a little vacation whenever we had a scene [together] because we're frolicking. It's kind of a time off for me because she's so deliriously happy; she enjoys his company so much.

"I don't know how tall I'm supposed to be, like 6'4, and he's what, 5'8 or something, and I tower over him - and you can really see it in the film.

"Being a tall woman myself, height doesn't matter at all. I love that we're mismatched. It's perfect."

Jack previously spoke of how "easy" he found filming with the Alien actress.

He told Entertainment Weekly: "I've been asked, 'Is it difficult?'

"But since Sigourney is Sigourney, she's so good at acting, and we're literally in a performance-capture Volume where it's grey.

"We know that our imagination is our main weapon. So when she's acting, it is very unique, but it was so easy 'cause she's such a good actress. I just reacted off her.

"So, I guess, it wasn't that hard, and it wasn't insane after the first couple days."