(Cover) - EN Showbiz - Robert Pattinson claims he looks like an "inflatable frankfurter" in his shirtless Twilight scenes.

The American actor is famed for his role as mysterious vampire Edward Cullen in the successful vampire franchise, based on the novels by Stephenie Meyer.

Robert and his Twilight co-stars Kristen Stewart and Taylor Lautner have been promoting The Twilight Saga: Breaking Dawn - Part 1 at the popular Comic-Con book, film and television convention in San Diego, California.

The film is the penultimate installment in the hugely popular film series, and Robert bares a lot of flesh in the picture.

The 25-year-old star says fans shouldn't expect too much.

"I don't want to get anyone's hopes up. I look like an inflatable frankfurter in some of those [scenes]," he quipped to MTV.

Robert has been fully clothed in the films up until now, despite Edward frequently not wearing a shirt in the fantasy novels.

The Hollywood hunk says he conjured up a number of options in his head to avoid having to be naked in the film.

"The thing I was most nervous about was taking my shirt off," he explained.

"I've managed to have my shirt on the whole series. In the book, [Edward is shirtless] almost every three pages. [I kept thinking,] 'How can I wear a T-shirt in the sea? Or a onesie?'"

The highly-anticipated honeymoon scene between Robert and his real-life girlfriend Kristen premiered at Comic-Con - with more than 6,000 fans gathering to catch a glimpse of the couple getting steamy in the sea. (C) Cover Media