What is the ruling on a suitor corrupting a fiancée who is emotionally attached to the one who corrupted her? And is it permissible for a man to propose marriage to a fiancée and then withdraw to give her freedom of choice?

A man is not permitted to propose marriage to a betrothed woman, as this may lead to the disruption of her engagement. This act is referred to as "takhmīb" if the general linguistic meaning of takhmīb is corruption, and Islamic law has prohibited proposing over another's proposal.