All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad is His slave and Messenger.
The wife has the right over her husband that he should have sexual intercourse with her, so he is obligated to have sex with her according to her desire and according to his ability as clarified in Fatwa 89569.
Also, he should live with her in kindness and fulfill all her rights, among which is to spend on her and on his children from her sufficiently. So, if he is stingily withholds money from her while he is well-off, and she can take from his money, then it is permissible for her to take from it to spend on herself and on her children within reasonable grounds even without his knowledge. Indeed, we clarified this ruling in Fatwa 92004.
Besides, if the wife is greatly harmed by staying with her husband due to him not having sexual intercourse with her, for example, then she is permitted to ask for divorce. Also, if he does not spend on her, and she cannot take from his money, then she has the right to take her case to an Islamic judge or whoever may act on his behalf, like Islamic Centres in non-Muslim countries, so that they would oblige him to spend on her or to remove harm from her by divorcing her from him. For more benefit on the situations where a wife is permitted to ask for divorce, please refer to Fatwa 88408.
However, a wife should take it easy and not hasten to ask for divorce. Rather, she should endeavor to solve her problems with her husband even by seeking the help of some of his friends who are righteous and trustworthy.
As regards the husband suspecting his wife and accusing her of cheating on him, then this is not permissible and this is bad suspicion which is Islamically forbidden as it is not permissible for him to accuse her of something bad without evidence. No doubt this is contradictory to living with one’s wife in kindness which is Islamically ordained. For more benefit, please refer to Fataawa 86618 and 88304.
On the other hand, the wife should protect herself (by wearing Hijab) and avoid places of temptation so that her husband would not think evil of her. Moreover, she should be concerned about his matters and beautify herself to him as such matters could lead to more affection between them.
Allaah Knows best.