In my work with partners of sex addicts, I always want to look at the role that anger has played for the partner.
Anger is a normal response to the traumatic experience of having been betrayed by your mate.
But it can also be a feeling that is difficult to tolerate. Some people dive into anger fully, while others avoid experiencing feelings of rage, and sometimes, people are afraid of their own angry feelings.
As a force, anger can be put to positive and constructive uses, and it can also be very destructive.