What is the ruling regarding a woman who has committed metaphorical fornication with a non-mahram man, then engaged in sexual intercourse with her husband, believing that intercourse with him was forbidden? Is this considered zina that necessitates a hadd punishment? And is it permissible for her to marry another man with whom she commits metaphorical fornication before repenting?

A woman's intimacy with her husband, while she believes it to be forbidden, is not zina (fornication/adultery). However, she incurs sin due to her audacity in doing what she believes to be forbidden. It is not forbidden for her to marry the man with whom this act occurred. She must repent from these forbidden actions, as it is an ugly disobedience and a clear reprehensible act. Repentance involves abandoning the sin, regretting having committed it, and resolving not to return to it. Part of sincere repentance is avoiding the causes of the sin and cutting off the paths that lead to it.