The Fifty Shades Of Grey film has failed to get critics hot under the collar - but is expected to be a hit at the box office.
The film version of EL James' raunchy best-seller is having its world premiere at the Berlin film festival tonight, ahead of its UK premiere tomorrow.
Starring Jamie Dornan as Christian Grey and Dakota Johnson as his lover Anastasia Steele, it is virtually guaranteed to be a box office hit with one cinema chain already boasting of more than £1 million in ticket sales a week before it opens.
But the first reviews which hit the internet gave a mixed response to the big screen adaptation of the X-rated book, which has sold more than 100 million copies worldwide.
Justin Chang, chief film critic at Variety magazine, said the film begins well and describes it as "glossy, well cast, and a consistent hoot".
He wrote: "In telling the story of a shy young virgin and the broodingly handsome billionaire who invites her into his wonderful world of hanky-spanky, director Sam Taylor-Johnson and screenwriter Kelly Marcel have brought out a welcome element of cheeky, knowing humour that gradually recedes as the action plunges into darker, kinkier territory."
But he warned that far from delivering an enjoyable climax, the film gets worse towards the end. And he branded the last half an hour "punishing in more than just a literal sense".
The Hollywood Reporter also gave the hotly-anticipated film a mixed review.
It said Johnson is "captivating" as the English literature graduate who falls under Grey's spell.
And it praises the film's "artful restraint" explaining that "the sex scenes suggest more than those of the standard Hollywood drama without quite going there".
But it warns fans that "it's a slow build to the smutty bits, and one that's disappointingly devoid of tension".
Cinemas are bracing themselves for massive sales as fans of the erotic book are expected to flock to the aisles to see it on the big screen.
While a leaked memo from DIY store B&Q said staff have been asked to prepare for an increase in demand for rope, cable ties and tape.
Earlier this month it was announced the film had been passed by censors without any cuts.
The British Board of Film Classification (BBFC) made director Sam Taylor-Johnson's take on the so-called "mummy porn" story an 18 certificate, but said the work "passed uncut".
The three books written by James have reportedly been translated into more than 50 languages
Taylor-Johnson admitted she had creative differences with the best-selling author, whose books have won legions of fans around the world.
She told Porter magazine: "It was difficult, I'm not going to lie.
"We definitely fought - but they were creative fights and we would resolve them."
She added: "We would have proper on-set barneys, and I'm not confrontational, but it was about finding a way between the two of us, satisfying her vision of what she'd written as well as my need to visualise this person on screen. But, you know, we got there."