Is it permissible for a husband not to inform his wife of his travel dates and other details of his life, and is it permissible for the wife to treat him in kind when she is angry at his mistreatment of her?

It is permissible for the husband to conceal matters related to his personal life and the date of his travel from his wife, as long as it does not lead to the squandering of her rights. Likewise, it is permissible for the wife to conceal her private matters that are not related to her husband's right over her. However, wisdom and good companionship necessitate that neither of them conceals from the other what poses no harm in being disclosed, in order to preserve affection and foster love. The Sharia (definition) has permitted each spouse to "lie" to the other in matters that do not involve the squandering of rights, such as feigning affection or making non-binding promises, but not deception regarding rights themselves. As for the wife treating her husband similarly by refraining from answering his questions, this is a form of abandonment which she is not permitted to reciprocate with her husband, due to the potential for exacerbating problems and causing family disunity. Both spouses must strive for mutual understanding and respect to achieve family stability, which is one of the most important objectives of marriage.