When Harry Met Sally famously asked can a man and a woman just be friends or does sex always get in the way. New comedy No Strings Attached asks the converse: can a man and woman just have the sex?

Despite his ubiquitous celebrity, while watching this, it occurred to me that I'd never actually seen Ashton Kutcher in anything.

I was expecting some kind of lobotomised Keanu Reeves but here he plays someone who is told to his face, more than once, that he has a good heart and you completely accept that: he's just so awfully kind and nice.

It probably helps that he is cast against Natalie Portman, who isn't.

Portman is the cutting, dominating, emotionally cold, career-orientated woman, while Kutcher is the big dumb loveable lunk who loves her.

On her insistence, they have a relationship based purely on sex – a situation which cannot be allowed to prosper, even in a film that fancies itself a bit sharper and more with it than the usual.

In truth, No strings Attached is about as 'now' as Malcolm Muggeridge's Twitter account, but it is definitely a lot sharper and funnier than the normal rom-com.

It's just that very little of it actually provokes laughter – probably because the characters and situations seem so artificial and forced.

Still, my better half thought it was lovely and romantic and it is at least making an effort.

No Strings Attached (15)

Director:Ivan Reitman

With: Ashton Kutcher, Natalie Portman, Greta Gerwig, Lake Bell, Jake Johnson, Kevin Kline

Length: 108 mins

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