If Heidi had known Tracey longer, knew her better and were closer, the emotion that flashed quickly across her features before disappearing could be clearly defined as jealousy. Once it was gone, her face returned to it's teasing seriousness. "Well, I don't think I'd get an accurate opinion. It's like watching someones reactions to a quidditch match and not seeing the actual match itself."
She bit her lip. She was obviously failing at not flirting with Tracey. Heidi didn't want her flirting, which was already a surprise to her, be a shock to Tracey and frighten her away.
Closing her book, Heidi pushed it out of the way as the Slytherin set the ingredients on the table. The explanations that Tracey were giving sounded complicated, but Heidi was sure if Tracey helped her nothing too bad would happen.