As a CATHOLIC Christian, I cannot accept that "adultery" is an acceptable reason for leaving a marriage. There are situations where a separation may be indicated--especially, if there is physical danger to the spouse or to the children. But not divorce.
Jesus replied, " Moses permitted you to divorce your wives because your hearts were hard. But it was not this way from the beginning. I tell you that anyone who divorces his wife, except for marital unfaithfulness, and marries another woman commits adultery." Matthew 19: 9
While I believe divorce is never the best choice (and for my husband and I, the word is not in our vocabulary), there is clearly one exception. And it's not in church doctrine, logic, or personal opinion, but in the words of Jesus, Himself.