"I..." Where was her fight that she wanted to put up? Where were her opinions and research and logic now, when she needed them the most? There was no happy ending to this. Stiles was leaving and he didn't want her to be hurt. On paper, it made plenty of sense, but in reality, it made her want to drive her head into a wall. He had made her open up to him, against what she told herself she would do; made her fall in love with him for who he was, and now, through some cruel twist of fate, they weren't going to be together. Typical.
"That isn't what I want, Stiles. Doesn't what I want matter at all?" She knew what his reply would be. In this scenario, she knew it didn't matter. "I love you. You made me fall in love with you and now you're just leaving! Why would you do that?" She didn't want him to go to Derek's because she knew that he had the same nobility problem that Stiles did. He would promise to stop Stiles if he got too dangerous, and Stiles would be lost forever. Lydia wasn't sure what would be worse to witness; Stiles getting worse with the hope of potentially getting better or seeing Derek fulfill that end of such a deal.
"Is that it, then? Are we just..." Saying it would make it real and Lydia didn't want it to be real. She just wanted this pain to stop for a second. "Are you just breaking up with me?" The question was asked without much emotion; her voice sounding hollow as she looked down at her entwined fingers playing rhythms on her legs.