you were at your locker grabbing your supplies when Dean and Sam were sprinting. Dean was laughing but Sam was nervous. Dean accidentally bumped into you, muttered "sorry" and stopped for a second, laughing while Sam was yelling at him.

Sam: DEAN!! Why'd you punch that kid??

Dean: HA! he was an asshole, what can I say? deans cocky smile was still there and he leaned against a few lockers down from yours