The singer-and-actor has claimed he didn`t enjoy shooting his sex scenes with co-star Mila Kunis in their movie `Friends with Benefits` because it is awkward acting out such intimate sequences.

However, Justin does enjoy watching other people get steamy in the bedroom, just like most guys do.

He said: "It`s (sex scenes) part of you`re job and we`re both professionals and we definitely pushed it to the end of the shoot. We took two weeks and shot all the scenes in bulk. I think that was wise.

"But there was nothing really sexy about it. We were in this bed, going, `Man I hope people think this is funny.` For me, personally, watching sex scenes is awkward, so we thought it was a good opportunity for comedy. (They`re awkward) because you watch two people f**k. I`m joking, I love watching sex - I`m a guy, so I like porn and sex scenes."

Justin had to get naked for the film - which sees the heartthrob`s character Dylan and Jamie, played by Mila, agree to have a sexual relationship with no strings attached - but insists he didn`t mind stripping off on screen because he is 30 and looks good.

Speaking in this week`s edition of Britain`s Star magazine, he said: "I am nude in the movie, but I think it was tastefully done and we`re always covered up. I think that I`m probably not going to be as game to show my ass when I`m 40, so I`ll do it now while I have less time to think about it."
sections: Celebrities