Here's another one:

Closer.

A very powerful and disturbing film. Two couples, both use sex as a weapon and truth-telling as a form of emotional torture. Set in London.

Funny, how it seems that the "nice guys" are the ones cheating and the "cruel" ones the ones being cheated on.

It's got some very powerful stuff going on. I don't know if I would have the ability to watch it now.