Agree with stricktlydating that she thought the grass was greener. Affairs seem new and exciting especially if there is problems at home. Forgiveness is in his court and needs to really think about this. Marriages usually have problems coming from both sides and need counseling. Bringing in a third person into a relationship never works and draws your attention out of the marriage when there is work to be done on that relationship. It is easier to run than to work on making a marriage work when times get tough.