Praise be to Allah.

Allaah has commanded the Muslim to protect himself and his family from the Fire. Allaah says (interpretation of the meaning): 

“O you who believe! Ward off yourselves and your families against a Fire (Hell) whose fuel is men and stones, over which are (appointed) angels stern (and) severe, who disobey not, (from executing) the Commands they receive from Allaah, but do that which they are commanded”

[al-Tahreem 66:6]

Allaah has put the wife and children under the care and protection of the husband, and he will be asked about them on the Day of Resurrection. It was narrated from Ibn ‘Umar that the Prophet (peace and blessings of Allaah be upon him) said: “Each of you is a shepherd and each of you is responsible for his flock. The ruler is a shepherd and is responsible for his flock; the man is the shepherd of his family members and is responsible for them; the woman is the shepherd of her husband’s house and children and is responsible for them; the slave is the shepherd of his master’s wealth and is responsible for it. Each of you is a shepherd and each of you is responsible for his flock.” 

Narrated by al-Bukhaari, 853; Muslim, 1829. 

Allaah has warned those who betray this trust and do not protect their families as required, that they will be denied Paradise. It was narrated that Ma’qal ibn Yassaar said: The Messenger of Allaah (peace and blessings of Allaah be upon him) said: “There is no person whom Allaah appoints in charge of some flock and he is not sincere towards them, but he will not smell the fragrance of Paradise.” 

Narrated by al-Bukhaari, 6731; Muslim, 142. 

What this husband is doing, watching pornographic movies, is an evil and a great sin. It is not permissible for him to do that, let alone force someone else to do it. 

If the husband calls his wife to watch these movies, it is not permissible for her to obey him, because the Prophet (peace and blessings of Allaah be upon him) said: “There is no obedience if it involves disobeying Allaah, rather obedience is only with regard to that which is right and proper.” Narrated by al-Bukhaari, 7257; Muslim, 1840. 

The husband’s threat of divorce does not count as a legitimate excuse for her, and is not regarded as her being forced to do it. Rather she should advise him in the way that is better. If he responds and gives up the evil that he is doing, this is something good that he is doing for himself, and she will be rewarded for that. If he refuses to respond to the command of Allaah to lower the gaze and avoid looking at haraam things, then it is not permissible for her to obey him in committing sin, and she should not trust him with regard to herself or her children, and Allaah will compensate her with someone better than him, in sha Allaah.