reasons: It involves poor child who are innocent, for whatever reason the mother had affair with other man. I don't really understand "pursue your own happiness, even if it means to abandon everything/one you used to love (husband, children, family)". Anyone should know marriage is not a 24/7 love story, quarrel fight jealousy should be expected in marriage.
Conclusion: don't get married and even think to have a child if you don't have the courage to walk through a storm. Because you will just end up hurting a lot more people.