Is it permissible to take money from a Christian woman, who is not a believer, to start a business venture, while maintaining a friendship and business partnership with her after repenting from repeated fornication with her? And is it permissible to marry her for the purpose of obtaining citizenship and money? And would marrying another woman alongside her be an injustice to her if she is not informed about the first marriage? And if marrying her is not permissible, is it then lawful to continue the relationship with her as a friend and business partner while being married to another woman?

It is Islamically forbidden for a Muslim to be in a relationship with a woman who is a stranger to him, and your actions with her are evidence of this. Repentance must be repeated, without despairing of God's mercy, and with hope, let there be fear of a bad ending. It is not permissible to continue the relationship with her, even through writing, as a preventive measure against corruption. Marriage to her is forbidden because she is unchaste (an adulteress), and even if she were chaste, some scholars disliked it due to the presence of Sharia-related caveats. If your wife is righteous, return to her; otherwise, seek a woman who is pleasing in her faith and character. Mere partnership and working with her is permissible in principle, but there is a fear that it could be a gateway to temptation, so we advise you to avoid her completely. If she gave you money because of the relationship, it is not permissible for you to benefit from it or return it to her; rather, donate it with the intention of disposing of unlawful wealth.