Are a husband's betrayal of his wife and a wife's betrayal of her husband equal in sin and punishment? Is it permissible for a husband to marry without his wife's knowledge? What are the conditions for polygyny for a capable husband if his second marriage will lead to the divorce of his first wife? What is the ruling on the husband and wife if the husband betrays his wife while he is capable of chastity, and then the wife betrays him?

Adultery is a major sin and a betrayal of Allah Almighty, transgressing His boundaries. There is no difference in its sinfulness between a man and a woman, whether married or unmarried. It is one of the most abhorrent immoral acts and a wicked path. Those who commit it will incur grave sins, and their punishment will be doubled on the Day of Resurrection, unless they repent. A Muslim must not contemplate disobeying Allah merely because others have done so. The punishment for adultery is the same for both men and women, whether they are married (muhsan) or not. A man's adultery with a married woman and a married woman's adultery are more severe in sin due to the resulting confusion of lineage. Polygyny is permissible for a man if he can be just and provide sustenance, and he is not required to inform his first wife, nor does it necessitate her divorce, unless she rejects Allah's command.