The answers are not so simple and can vary significantly by what your values are. While some argue that even a thought of another person may amount to committing (emotional) adultery while others approve of adultery when your relationship is dead but you are still together for whatever reason. The latter opinion is very popular among many cultures where divorce is not an option but the marriage exists only for the sake of the society.
Michael has written about Betty, a friend who became a widow recently. And then she bumped into a long lost boyfriend from high school who has been married all his life to the same woman. He writes, "I have been very supportive to her about this new relationship. I commented that his marriage must be over or he would not be calling and visiting her. I also suggested that she live each moment and not worry about his problems with his wife; that's his problem. They live over 1000 miles apart but he travels on business every month so he can see her. Obviously, his wife chooses not to travel with him on business trips. Your thoughts would be appreciated."
I am reminded of a similar story of how a couple who were friends in high school met after many years and had a relationship. I know for sure that in most cases adultery creates complications rather than solve any problems. If the other partner is clueless and trusts her/his partner completely, an unfaithful partner is doing a terrible thing by committing adultery.
So in my opinion, Michael's friend is not doing the right thing even though I have approved of adultery in some cases. And her old flame is not doing justice to either of the women. He is cheating his wife and Betty both. It is perfectly fine to pursue a relationship after widowhood but what if her old boyfriend does not want to give his complete self to her. The relationship is then meaningless. Betty has to ask herself what is she accomplishing by being in this relationship. Is it just reliving the old times? Or is it just intimacy? Does she realize that she may be destroying a family?
And let me conclude that it is not entirely Betty's fault. Her boyfriend has to think of the consequences of his actions too. Is he unhappy with his marriage? Why doesn't he do something about it? If he likes Betty so much, they can still be friends but not get into a relationship.
The questions about marriage and adultery are rarely so black and white. Both Betty and her boyfriend need to weigh the pros and consequences of their relationship and decide what can they live with without feeling any guilt. And what can Michael do? As a good friend, he needs to help Betty answer some questions that I have raised and let her try to answer them. It is not for him to judge her or decide for her. Good friends are there no matter what! But they do help their friends think through complex issues.
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