(Cover) - EN Showbiz - Robert Pattinson once had a sex scene banned from a movie because it was "too emotional".

The star is promoting the latest Twilight movie Breaking Dawn Part 1, in which his character Edward Cullen finally sleeps with Bella Swan, portrayed by Kristen Stewart.

Much has been made about the scene as parts of it had to be left out to assure a child-friendly rating. Robert insists that is only because the system for classifying movies is so "weird".

"The ratings board is very strange, you're judged on such specific things. They'll be like, Oh that noise! You can't have more than six noises during sex scenes.' I did another movie where they said the sex was too emotional, so we had to make it less emotional. It's so weird," he laughed.

Bella and Edward have a child together, and Robert struggled to shoot some of the birth scenes. He worried the set was too dramatic and realistic and still dislikes thinking about it because it affected him so badly.

"I think it was more horrific filming it [than watching it]," he told the Kyle and Jackie O radio show. "I think it would be impossible to show the full extent of what the set looked like without it being R rated. I remember walking onto the set the first day and they had this prosthetic dummy of Kristen and it was so emaciated with this huge mutated baby bump and her rib cage was sticking out and she was just lying there like, dead, [like a] zombie and she's covered in blood wearing these rags. I was like, Jesus, how are we supposed how is this ever going to be in the movie' Oh man, it was horrible." (C) Cover Media