'Thor' Star Chris Hemsworth on 'Intimate' Scenes with Natalie Portman

The mighty 'Thor' is the next Marvel Comics superhero to hit the big screen, and Aussie star Chris Hemsworth details the amusing reality behind his intimate scenes with co-star Natalie Portman!

"The intimate stuff, you have to laugh at it," the newlywed Chris tells our own Samantha Harris. "On one hand there's an intimacy, but you're also in front of 50 people and there's some cameras pointing at you, so it's kind of not intimate."

Chris says he congratulated Natalie on her 'Black Swan' Best Actress win on Oscar night, and has true confidence in her upcoming real-life role as a first-time mother. "She'll be incredible," he says. "She's wanted to have kids, I'm sure, for a long time, and is a lovely, caring human being and ticks all the boxes, so she'll be great."

In theaters May 6, 'Thor' finds the arrogant Norse warrior forced to live among humans as punishment after reigniting an ancient war in his world. His true mettle is put to the test when a villainous foe sends dark forces from the realm of Asgard to invade Earth. The Kenneth Branagh-directed movie features Anthony Hopkins, Stellan Skarsgard, Colm Feore, Idris Elba, Kat Dennings, Clark Gregg and Rene Russo.

Chris says that despite the intimidating pedigree of some of his co-stars and director, he felt quite comfortable in his work environment: "My voice and opinion mattered and it was a very collaborative, fun set to be on," he offers. He admits that the workouts and diet required to bulk up for the character were not as fun, however.

"That has been the most strenuous and exhausting part of all, to be honest; the workouts are fun in moments, but sixth, seventh day that week, after 16 hours of other work, it's tough," he explains. "And the eating, the amounts of protein and food I have to consume to sort of keep the weight on, was a feat in itself. … All the fun stuff -- pizza and hamburgers and anything that tasted good -- was off the list; it all became about plain, dry chicken breast and steak and fish and vegetables and fruit. Look, it's great, it's healthy food, but after a while it gets a bit mundane."

Watch ET for more with Chris Hemsworth!