A man has two wives, one of them asks him what he did with the other wife because of being jealous from her, is it permissible for her to ask this question? It is permissible for him to answer her question?

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.

If what is meant in the question is that she asks him about his marital relationship with her and sexual intercourse with her, then it is not permissible for him to answer her question and it is not permissible for her to ask this question. This has already been discussed in Fatwa 88071. However, if what is meant by the question are other things, then the matter depends on the husband himself, he is more aware of what is beneficial to inform her about and what is not beneficial according to the effect that he sees his words will have on his marital life.

Allaah Knows best.