The two actors, who are rumoured to be dating in real-life, stripped off to film a series of saucy shots for the first installment of the vampire franchise's two-part conclusion, The Twilight Saga: Breaking Dawn.
Stewart, who plays Bella Swan, has now revealed the footage was so racy, the movie was given an R-rating, which bans viewers under the age of 18 seeing the film without an accompanying adult, so film bosses re-edited it to make it more appropriate for teenagers.
She tells Glamour magazine, ""It was so weird, it didn't even feel like we were doing a Twilight film. I was like, 'Bella! What are you doing? Wow! What is happening here?!' It was very surreal. We (originally) got rated R. They re-cut it.""