What is the ruling on a young man's relationship with a girl, intending not to marry her, while informing her otherwise, and how can this relationship be ended without hurting her?

It is forbidden to establish an emotional relationship outside the framework of marriage due to the temptation it entails. The best remedy for those in love is marriage. If marriage is not possible, the relationship must be severed to protect oneself. It is not permissible to delude a woman into believing one will marry her if the intention is otherwise. Rather, one should remain silent, which implies a lack of desire, or gently state it if necessary.