She opens her mouth to start to say it, and then gets a twinge of a headache. She calls this the Sirius Black twinge. It starts at her eyebrow and just goes down to her jaw, and is a bitch.

She takes what she hopes is a menacing, imposing step towards him, and hisses, "Listen you, I am not dealing with drunk giggles in the dorm well past midnight, so if you both - actually, scratch that, if all of you know what's good for you, you'll leave the punch alone and not get my roommates drunk tonight." She pulls back with a sniff. "I've exams to study for."