Even in her past life, her initial wariness of him got their relationship off to a bad start and he slowly won her over. I’m guessing because he realized she was the “maid” that helped his brother. Their relationship was less romantic, more friendly and he was devoted to her, mostly because she wasn’t allowing herself to love and be loved until very close to the end.
In this timeline, when she initially meets him, his expression makes her think he actually dislikes her more than in the past, and she’s very wary because she’s already changed the past. She misunderstands his constipated looks as hate when he really just wants to jump her lol. (And now he falls faster because he knows she also helped Enoch and rescued his brother’s remains). By now she’s realized that he doesn’t hate her, but she’s confused by his passionate response to her since their past relationship wasn’t like that. Therefore, she’s adjusting. However she’s also probably telling herself that their passionate relationship can’t be real because she has to leave/die in a few months (in denial, too good to be true, etc). Her aim in this timeline wasn’t love, but saving everyone
Why does the main character believe the ML hates her? Isn’t the whole premise of the story that he was the only one that showed her love in her previous life thus she doesn’t want to repeat the past where she kills him??? Just a little confused with her sudden thoughts about ML