Gryffindor: That moment when someone catches you staring at them, failing whilst attempting to do some sort of trick/skill in front of people, laughing in a very serious situation.

Ravenclaw: Dropping your stuff in a crowded hallway/area, confidently answering a question to soon figure out its wrong, pushing a pull door.

Hufflepuff: Calling someone the wrong name, waving at someone to soon realize they weren't waving at you, yelling out so someone then realizing it wasn't them.

Slytherin: Realizing your fly has been down for who knows how long, stuttering your worlds in front of the entire class/someone you like, talking very loud but not realizing until someone points it out.

Written by yours truly :)