Just saw it.
Sorry, this is gonna be a bad review.
Hubby, daughter and I saw it together and none of us liked it.
The idea of it was so nice, too bad it was ruined. The film tried much, much too hard to be artsy, intellectual, prized - whatever. Instead, it ended up with the worst mistake a movie can make: it was boring.
There were some nice scenes in it, but not enough to carry such an overly long movie, not by a far cry. Of the three main characters, one went on my nerves, to one I was totally indifferent, and only one of the three was at least likeable, but still boring.
****WARNING*************SPOILER**************************
On the upside, I liked how the relationship between the original couple developped: from bored almost-phlegm to understanding and sweet care for each other. Once they both had started an affair with Adam (the third guy) things started to liven up a bit (but it took way, way too long to get to that point). And of course I liked the idea of tolerance and understanding, of including a third person into their intimacy.