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.
We have already issued Fatwa 89109 clarifying that it is not permissible for a wife to suspect her husband without evidence, especially if this is about accusing him of adultery.
Therefore, if you have no evidence that he does so, then you should not keep thinking about this matter, but keep your heart free from the doubts which may make your unhappy.
If we presume that you have evidence about this, then you should advise your husband in a nice and soft manner and be wise in doing so, and you should beautify yourself to him and fulfill his needs so that he would not think about other women instead of you.
For more benefit, please refer to Fatwa 86796.
Allaah Knows best.