What is the ruling regarding a wife who suffers from her husband's pornography addiction and his frequent sexual demands despite her exhaustion, which affects her studies, while she fears divorce for the sake of her children, and is it permissible for her to refuse intercourse sometimes?

Watching pornographic films is forbidden for a husband. However, a wife must obey him if he calls her to bed, unless she has a legitimate Shar'i excuse such as illness, menstruation, an obligatory fast, or a confirmed harm from intercourse. A wife's refusal to go to bed due to lack of desire, fear of falling short in studies, or his frequent requests for intercourse is not permissible. Similarly, it is not permissible to refuse to go to bed as a punishment for the husband's actions, because that might aid Satan against him. Rather, she should strive to keep him chaste, to be an aid for him in repentance and uprightness. It is recommended to be patient and supplicate for his guidance, and not to despair of his reform.