He only just held back a genuine gasp at the idea of sneaking into Hogsmeade before third year - how did one get away with such a thing? "But now you've only given me grounds to make an investigation. Perhaps I have ways of making you talk and reveal every deduction-worthy offence you've ever committed." The words may have sounded completely serious, but they were accompanied by a twinkle in Percy's eye.
"Something tells me you were far from perfect, young lady. Yes, I'm certain I would find many an infraction in your history, though I wonder if points deduction would be sufficient punishment for them all."