The pair play best buddies who decide to become Friends With Benefits but things start to get complicated when Kutcher's character Adam starts to fall for Portman's Emma.
As he desperately tries to woo her, Emma is determined to keep things purely sexual so Adam hits back by trying to make her jealous.
Director Ivan Reitman, who made My Super Ex-Girlfriend, told USA Today: 'I noticed from my own kids that with this generation in particular, young people find it easier to have a sexual relationship than an emotional one.'
'That is how the sexes deal with each other today.'
Portman seems to be trying her hand at more light-hearted films at the moment.
She'll also be appearing on the big screen as a potty-mouthed warrior in fantasy comedy, Your Highness.
No Strings Attached is released in the US on January 21, 2011.
source:metro.co.uk
