Justin Timberlake's sex scenes with Mila Kunis in Friends With Benefits were "awkward".

The Hollywood heartthrob and the brunette beauty play lovers in the upcoming comedy movie, and Justin admits it wasn't easy getting romantic in front of the cameras with Mila

He said: "I'd be lying if I said filming the sex scenes wasn't completely awkward ... The producers and I agreed we would shoot a big chunk of the movie before we got down to the sex scenes, which was a good idea. That allowed Mila and me time to get comfortable. It wasn't that I didn't want to go all out for this."

It had been predicted that his scenes in Friends With Benefits - which focuses on two professionals who agree to have a sexual relationship with no strings attached - wouldn't be the only awkward moments on a film set for Justin.

He stars with his ex-girlfriend Cameron Diaz in new movie Bad Teacher, which see's the actress' character Elizabeth Halsey romantically pursue Justin's alter-ego Scott Delacorte, but he insists things were fine between them on set.

The singer-turned-actor - who dated the blonde beauty for almost four years until December 2006 - told Playboy magazine: "It sounds complicated to everybody else, but it wasn't to us ... We don't talk to each other all the time, but we respect each other, and on some level we'll always love each other - but in our new capacity as friends. I think the world of her."

- BANG! Showbiz