Sam Riley didn't ''bat an eyelid'' during nude scenes in 'On the Road'.

The 32-year-old actor - who plays Sal Paradise in the upcoming big screen adaptation of the classic novel - revealed that despite getting close and intimate with co-stars Kristen Stewart and Garrett Hedlund, they were at ease with each other and even joked about nakedness.

He said: ''Man. I've seen his [Garrett] penis more than I have my own brother's! By the end of it, I didn't bat an eyelid.

''There was a scene where we all sat naked on a rock together, which never made it into the film, but it was so funny - we never looked down, we just looked at each other, like, 'You all right?'', 'Yeah, I'm fine, yeah.' ''

The 32 year old also admitted that he took the role of Sal without having read Jack Kerouac's cult novel and feels like he missed out on it when he was younger.

He added to ShortList magazine: ''I didn't read it. I missed out on the book when I was a young man. A lot of my friends read it, and then they went travelling and things like that.

''Around that time I was having to read books for my A-levels. I dint want to read anything else.''

The film sees Sal's life shaken up by free-spirited Dean Moriarty and his girlfriend Marylou - played by Kristen - as they travel across the country and encounter a mix of people on their journey.