You aren't in the right headspace, which is reflecting on her. She's tired of your odd behaviour and less than ideal treatment. So when you snap at her once more, she stands up and crosses her arms, eyes narrowing.

"Okay, seriously? This isn't okay anymore. Stop being such an asshole!" She says. She'd wanted to give you the benefit of the doubt, but it's too much now. She's not gonna let you treat her like some chick you're seeing.