Kitty didn't know what exactly it was that did it. Perhaps it was being compared to an infant, or Seth suggesting that all he could be blamed for was for if she got hurt while out here, but whatever it was, something in her definitely snapped. She was still crying - and by, God, it didn't look like it was going to stop soon, but jerking her hands away from her face, she turned and glared fiercely at the boy sitting a few feet away from her. If she thought she had come here angry, she had no words for what this was. Perhaps just some form of sheer desperation to assert herself now that all that she had once believed had been stripped away.
"No, do you know what, Seth?" she snapped, spitting his name out like it physically hurt her, and stood up, approaching Seth with a kind of fire she had never felt in herself before, "You can get the hell out of this courtyard, and I'll leave whenever I damn well like! Got it?" And damn, a curse word (by her standards, anyway) had been dropped in. She really was mad.
"I'm far from an infant, and I'd just like to see you try to get me to go anywhere." she challenged, and a huge part of her was thinking 'oh God, why Kitty just shut up now maybe it'll be fine' but the much bigger, much angrier part wasn't going to take this at all. Everything she had held true had been shattered that evening, and she wasn't going to be mocked by Seth on top of it.