well the boy kinda ignored her so thats bad but i think it was because he knew the girl was with the prince, though she didnt do it for hurting him or anything but because she was in love with the prince, its not good to be cheating when they are engaged (i do get that they didnt have feelings but still is not respectful, just imagine if it was him the one cheating) and i also know the girl was a victim of the prince, but it was still her choice to be with the prince while she was engaged
im trying to give a lot of points of view, you may know most of what i said, and i problably forgot something and maybe the boy is more of a bad guy than i remember jwjsjsu sorry
is so cool to know that his fiance never did anything wrong to her, because otherwise it would be like most reincarnation manwhuas where the ml falls for her bc of the personality change when before they were so meann˃ ⤙ ˂,, to be honest the one who did him wrong was the before-reincarnation mc