What is the ruling on a wife's feeling of aversion to the marital relationship when she sees her husband watching foreign films that contain explicit scenes, along with her fear for her children from watching such content?

Watching such movies is not permissible due to the corrupting elements they contain. It is your duty to gently advise your husband and inform him of the scholars' rulings regarding the impermissibility of downloading and watching these movies. This is alongside your obligation to obey him in what is good, especially concerning the conjugal rights, as it is not permissible for you to refuse him without a valid excuse. If you fulfill your duty of advising, then there is no sin upon you for what your husband does. Beware of conflict, discord, and excessive argumentation. Seek Allah's help and strive for excellent companionship with your husband, good treatment of him, and supplicate for him.