For those of you interested in seeing a delicate and sensitive portrayal of a S/M relationship, I would highly suggest the Japanese film, "Moonlight Whispers" over "Maitresse." That film is a gentle coming-of-age film with male sub/fem dom theme, while "Maitresse" is a somewhat confused film about an ex-con who stumbles into a dungeon and a (highly unlikely) vanilla relationship with a dominitrix.
The ex-con cannot deal with "her career" eventually and threatens her to quit, etc. (At some point, you get the idea that the director himself really doesn't understand where the Domina is coming from.)
What started out as an interesting film with a provacative opening soon falls apart about halfway through. The writer/director seems to lose the narrative thread of the film and things degenerate with the ex-con wanting to buy the dominitrix out from her protection (or pimp, for want of a better word). Then, we watch as the ex-con -- in a totally unrelated and gratuitous foray -- goes to a slaughterhouse, where a real horse is shown killed onscreen, strung up and stabbed and drained of blood as it kicks helplessly (this image will upset you for weeks, believe me! [I feel like it's my duty to WARN YOU!]). And the film gets even worse from there and finally ends up with a ridiculous car accident and the two main characters laughing like idiots. Totally stupid (like the writer/director suddenly ran out of ideas).
Believe me, I really WANTED to like this movie. I ignored the negative reviews, because there are so few "real" films on this subject. But I was sorely disappointed and depressed by it.
If you need to see this film, rent it. It's definitely a "one view" film at best; and it will be a film that will leave you angry (because the horse scene) and vaguely disgusted -- and generally bummed out. Too bad.
"Moonlight Whispers" is a much better, respectful treatment of S/M, a film with real characters and nuance -- one that seeks to explore real psychological (and sexual orientation) questions, while also being a beautiful film to watch. That film deserves to be seen -- and a wider audience!