What is the ruling on the behavior of a husband who insists on engaging in sexual activity with his wife from behind (without penetration), despite her strong rejection of this act and her knowledge of its impermissibility, believing that she enjoys and desires it, which causes disputes and estrangement between them?

Enjoying the anus without penetration is permissible and not forbidden. Imam Al-Shafi'i and Ibn Qudamah explicitly stated this, as mentioned in the commentary of Al-Dasuqi, because the prohibition is specific to penetration. However, this act is disliked if there is a fear that it might lead to anal intercourse, as scholars disliked it because it tempts one towards the anus. It is advised to reach an understanding with the husband, strive to advise him, and help him maintain his prayers.