Robert Pattinson and Kristen Stewart
Kristen Stewart already called their on-screen sex scenes
"surreal" – but Robert Pattinson
uses other words to describe filming their intimate moments.
"It becomes ridiculous after a while," he tells Parade
about what runs though his head when he has to get intimate with Stewart.
"I think the more comfortable you are with each other, the harder it gets to do any kind of really intense relationship scene. You're kind of thinking, 'I don't want to embarrass myself in front of this person.' "
Pattinson, 25, who's been dating his Breaking Dawn – Part 1 costar
, 21, for several years, acknowledges the awkwardness, saying, "Watching other people have sex is never going to be that spectacular anyway. It's a strange thing when there's so much hype about it. You are like, 'God, I hope this lives up to it.' "
In fact, the scenes
in question actually had to be reshot
so as to avoid a R rating by the MPAA, which would limit its audience. (The movie, rated PG-13, opens in theaters Nov. 18.)
"The toughest part was avoiding an R-rating," Pattinson says. "It's funny when people talk about the sex scenes in the book because there are no sex scenes in the book. Go back and read. They always fade to black."
Meanwhile, director Bill Condon told MTV News
that the love scenes were "so much more about romance than it was about hot-and-heavy action."
Nevertheless, Pattinson will be showing some skin for the first time in the franchise – and it wasn't without forethought.
"I managed to get through the entire series without taking my shirt off the whole time," he says. "Then, when we did Breaking Dawn
, I thought, 'It's the last one. I might as well.' "
"So I kind of worked out to bulk up a little for those scenes with my shirt off," Pattinson continues. "I stopped literally the day afterwards. I find it very boring to work out."