Justin Timberlake getting along well with co-star Mila Kunis

American singer/actor Justin Timberlake and Mila Kunis have been getting along well on the sets of their new film ‘Friends With Benefits.’

At only 5ft 3in, the 26-year-old actress star's height makes her the perfect pint-sized package, but it's causing problems on set - she was forced to stand on an apple box while filming scenes with Justin, 29, on the streets of New York to make sure the pair's heads were both in shot.

“It was hilarious to watch, Mila is so much smaller than Justin that they couldn’t say their lines together on camera - she was basically talking to his chest,” News Of The World quoted a source as saying.

Meanwhile, Mila is head over heels in love with child actor Macaulay Culkin. She has been dating for the past eight years.