Il compromesso (Frontiere)

This is Eddie Anderson's story. He's successful, well-off, with a nice home and an attentive wife. But he's restless. So he has a mistress, and now she wants to change that arrangement. How Eddie got in this mess and how he tries to get out is the story of this best-selling book.
Elia Kazan won two Academy Awards for directing before turning to writing.

"THE ARRANGEMENT is about those 'arrangements' by which we live, in marriage, out of marriage, between marriages. It is an earth-shaking book and the earth it shakes is the plot on which we're standing." (Publisher's Source)