What is the safest religiously permissible way for a young man to return to his former fiancée, and is it obligatory to inform her current fiancé of the truth, or must the young man explain the situation to her fiancé himself?

Dating between young men and women is impermissible due to the corrupting consequences that result from it. Speaking with a non-mahram woman is permissible only when there is a legitimate need, provided it is done with modesty and shyness. Justifying speaking with her by claiming it is for religious matters is a deception from Satan and a means to corruption.

It is not permissible to propose to a woman who is already engaged to another Muslim man, based on the Prophet’s (peace be upon him) saying: "A man must not propose to a woman to whom his brother has already proposed, unless he marries her or gives up the proposal." As long as the engagement is still valid, it is unlawful for you to propose to her or to speak with her. What is obligatory is to repent and to break off your relationship with the girl.

As for the girl, if her fiancé is of good character and religious commitment, we advise her not to break off the engagement and to adhere to Allah’s limits. If she does not wish to marry him, she is permitted to break off the engagement without stating a reason. In that case, it becomes permissible for you to propose to her through her guardian.

Remember Allah’s saying: "But perhaps you hate a thing and it is good for you; and perhaps you love a thing and it is bad for you. And Allah knows, while you know not." (Al-Baqarah: 216).