Is a young man obligated to marry a girl with whom he committed an error merely because he was engaged to her, and if he does not marry her, is he obligated to inform his future wife of what happened? And what is the expiation for his sin before Allah and before the girl's father?

"You are not religiously obligated to marry the girl or to inform your wife about what happened. You must conceal your sin, for Allah loves concealment and dislikes the disclosure of sins. Repent to Allah Almighty with remorse and a firm resolve not to return to the sin, for 'the one who repents from a sin is like one who has no sin.' Treat people as you would like to be treated, and do not do with other people's daughters what you would not approve for your own female relatives. Fear Allah and increase your seeking of forgiveness, and look for a wife who possesses faith and good character."