lock flipping

the act of opening a lock used on a locker, and re-locking it backwards so the person will have a hard time opening it

lock flipping usually occurs in middle schools, especially in gym locker rooms, to flip a lock one must know the combo, or (more likely) the lock was left open by accident.

crap i left the lock on my gym locker open, when i came back my stuff was thrown everywhere and my lock was flipped.

people who practice lock flipping are assholes