I’m just saying this because it’s my own opinion so I'm not sure, but I believe that the ML might not actually be the child of an affair but a different person or the fl is not the biological child of her father as claimed. The two characters will probably be in a relationship if this going in the direction I think it’s going. Again I do NOT know the rest of the story but to everyone jumping to conclusions and saying this is incest please wait for the lovely translator(s) to give us chapters and figure this out together