Josh Hutcherson shot a sex scene in front of his great-grandmother

Josh told Variety: "I've seen some questionable things over the years that my great-grandma has even seen. My great-grandma was on the set of the day on Future Man that we were shooting an orgy."

The Hunger Games star added: "I didn't realise the day she was coming also lined up with the orgy shoot. She was coming no matter what. She was going to be there. She's a very supportive great-grandma."

Josh explained that his elderly relative had a relaxed approach to the explicit content.

He said: "It was comedy. It was comedic. I was fully, well, not fully clothed. Grandma was like, 'You know, it's fiction. Very interesting, your job, Joshua.'

"My family can hang."

Rachel added that her parents are relaxed about the sex scenes because they have seen her get intimate in previous shows.

The 30-year-old star said: "I warned my parents.

"It doesn't matter because it's still going to be shocking but also, they've seen it before. They've seen my previous work and I've had sex in that, too.

"They're sex positive. My sex positive queens - my parents!"

Meanwhile, Josh had another awkward moment during filming when he farted in Tom Hanks' face as the pair worked together on the 2004 animated movie The Polar Express.

Recalling the embarrassing incident, Hutcherson explained on The Late Late Show with James Corden: "We're shooting this scene where he's playing the hobo and he's on top of the train, skiing down, and I'm nestled under him, and we're like, 'Whoa, this is crazy.' I farted."

Josh explained that the two-time Oscar winner wasn't amused at the time but he now considers the moment as a "rite of passage".

The star, who was only a child at the time, said: "I farted in the scene, it happened, I did it and instead of playing it cool, Tom Hanks is like, 'Whoa, whoa, oh my God, this kid, what the heck.' My first big movie and I just farted in his face.

"It was a rite of passage and looking back on it, it was very funny, but at that moment, I thought my face was gonna just start sweating blood."