Well I don't know how to explain the Park Sirin spoiler since it's kinda complicated, but the thing is she hates all NPCs (just like every average game player)
Actually i read in a spoiler in beginning chapters that park sirin interferes in the middle of game and conceives korin's child somehow. When korin comes out of the game and finds out about his child and park sirin, he does get angry and says he won't love park sirin ever because of her past deeds but for the sake of his child he will marry her, and also he will mostly raise his child by himself and she can only meet him from time to time.....so his child doesn't feel deprived either and won't even get influence from his crazy mother