Is it permissible for a man to marry the woman he loves after having sinned with her, with the opposition of his parents who are unaware of his sin and believe she is the cause of his home's ruin, preferring him to remain with his current wife who harms the children and makes them despise his family, or should he obey his parents for fear of what people will say?

If the brother has committed fornication (zina), he has committed a grave evil that necessitates sincere repentance (tawbah nasuh) by desisting, regretting, and resolving not to return to it. He should not marry the woman with whom he committed fornication unless she also repents. Obedience to his mother in refusing to marry this woman is obligatory, unless he fears falling into the unlawful, as obedience to parents takes precedence over marrying a specific woman. He should strive to rectify his current wife, but if their marital life does not improve, then there is no blame upon him for divorcing her, and he is not bound by his parents' obedience in not divorcing her.