Shame – a shamelessly honest movie that’s about much more than sex.

One thing for sure, there is plenty of sex in this movie. Nothing is hidden as far as nudity is concerned so you are kept well-informed about what is going on in that particular department. Full marks then to Michael Fassbender as the sexually active Brandon Sullivan and to Carey Mulligan as his equally uninhibited sister. They both manage to stay painfully in character even when they are uncompromisingly naked. This is not a pornographic movie – far from it – the more Brandon does it, the more you wish he could stop. Someone should take him home for a nice cup of tea and some cherry cakes, poor man, because sex for him is a compulsion and ultimately an agony just like any other addiction. When the moment, er, comes in a scene with two prostitutes, Fassbender’s face, shot in close up, must be the most anguished expression of orgasm in the history of cinema.

Sexual addiction is a serious subject, definitely not the subject matter for a titillating movie and director Steve McQueen, treats the issues with respect whilst, mercifully, not including a single earnest psychotherapist, caring social worker or human resources officer anywhere in the drama. This is a movie with long silences, heavy breathing and lingering shots of faces – aroused, bemused and in pain often set to music with the equally anguished Glenn Gould playing Bach. The New York subway is one of the co-stars, intercutting its solitary commuter melancholy with scenes in Brandon’s fastidiously ordered bachelor apartment and his soulless but stylish office. The subway moments are shot through with crotch-hungry looks, melancholy daydreams and, ultimately, the loneliness of crowded places.

Michael Fassbender exposes more than you see in a performance that dominates every shot – finding facial muscles for even the subtlest of mood changes and, often as substitutes for the minimal dialogue, he creates a depth of character that says more than is written.

He is not just a moody guy though just as the movie is not all sturm und drang. We are shown just what he is missing when he lightens up for Miss Normal, the highly eligible and wise Marianne from the office (Nicole Beharie) on a date that promises commitment. The scene in the restaurant where both Brandon and Marianne have no interest in the menu is enlivened further by a winning performance from the hapless but enthusiastic waiter (Robert Montano).

This movie has an epic cast of eloquent minor and non-speaking characters who populate the side streets, bedrooms and late night trains on Brandon’s long descent into Hell. None is more expressive than the woman credited as Woman On Subway Train (Lucy Walters) –  her agent will have to work hard to make this role sound as impressive as it was – we could feel the windows on that train steaming up.

Carey Mulligan as the neurotic erotic Sissy is from her first appearance an accident waiting to happen and she never disappoints. Her finest moment is her dangerously slow rendition of the classic song New York New York where she delivers each word as if it were a lightly-sucked olive from the driest of dry martinis.

So not a film for a first date maybe – it will give you much to think about but you will both want an early night and a comforting mug of cocoa.