It was a Slytherin Vs Gryffindor match. You were the Slytherin seeker so you were up against the Chosen One.. you needed to win. so you played as hard you could. unaware of your head of house just below you.. having his full attention on you. and Harry ofc.

When Gryffindor won you felt cheated! They won unfairly!

You were pissed so you and your team decided to march back to the changing room but you stayed behind.. talking to one of your Hufflepuff friends