When we are hurt...we feel angry and want to take revenge . In anger, we are unable to see the incidence from different angles.
We become consumed with thoughts of hurting the person,...who hurt us. As far as such s*xual transgressions are concerned, there are complex psychological reason why people end up behaving this way...why they behave in risky manner.
Sometimes, the person dionot intend to hurt the other but has acted wrongly for some other reason such as curiosity, deprived of s*x, stressed due to some other cause, depression and boredom...and many more possible resons. Somrtimes two people had subtle agreement but later, due to too much guilt feelings ...one has to put all the blame on the other.
With maturity and undestanding of meaning of such human behavior, it is possible to forgive and move on with one's life.
Harboring a lot of anger is like keeping the fire burning in your heart...it hurts you as much it hurts the other.