"I know about their Quidditch team and the ones we have classes with, I guess..." He trailed off, but then he caught what she'd said and went all wide eyed and immediately protective. "What did he do? Who was it? What was he doing?" He didn't like anyone messing with his sister, or his friends, or his sister's friends. With all three of those things, that was pretty much everyone in Hufflepuff covered.