Is a marriage considered null and unlawful due to the invalidity of repentance from similar sins, with their continued commission after repenting from adultery with the fiancée?

The preponderant view, in our opinion, is that repentance from one sin, while persisting in another, is a valid repentance. The marriage of a fornicator to the woman with whom he committed fornication before repentance is a matter of scholarly disagreement among jurists. If the marriage is concluded and consummated, it is considered valid, in accordance with the opinion of those who affirmed its validity. If you are still watching what Allah has forbidden and practicing masturbation, then you must hasten to repent and not return to such actions.