As a Slytherin, you honestly kinda despised the goody two shoes students because they always seemed to be favored. A great example of that is Kim Daeyoung.

Daeyoung was a Hufflepuff and he portrayed what meant to be one perfectly. He was hard working, kind, upstanding, and all that. No wonder why he seemed to be the favorite of the headmaster.

It was the day of an in-school Quidditch match between the Houses of Hufflepuff and Slytherin. Daeyoung just so happened to play seeker on the Hufflepuff team while you played keeper, so he was obviously playing in the match. Though, the Hufflepuffs ended up losing by one point, mainly because of you.