Professor Snape looked past Fleur to Lavender. "Are you certain, Professor?" he inquired in a bored tone that oddly held a hint of malice. "I suspect that many have tried before you to break that one's urge to trouble making without success."
Lavender giggled madly before stifling it causing Snape to regard her with a cocked eyebrow. "Sorry, Professor, I was…thinking of something else."
"Is your sister particularly adept at brewing potions, Professor?" Snape inquired.