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 ask Allaah to exalt his mention as well as that of his family and all his companions.
In principle a Muslim is innocent and we have to consider him as such unless proven guilty. Allaah says (which means): {O you who have believed, avoid much [negative] assumption. Indeed, some assumption is sin.}[49:12]. The Prophet said: "Beware of suspicion, for suspicion is the worst of false tales." [Al-Bukhari and Muslim] So it is not permissible for you to accuse your husband without evidence as this is very serious, especially if the accusation is about adultery, even by expressing this indirectly. This is a kind of accusing a chaste person, and the accuser deserves to be punished by being flogged eighty stripes. You do not have to investigate in this matter, neither by seeking Istikhaara nor by any other means. Such investigation is not founded even by Islamic Law. So we advise you not to think about this matter, as you might regret it in this life and in the Hereafter.
Allaah knows best.