crack action. when you display your butt crack in really low cut bottoms. this is most common in trashy girls, fat chicks, and when pants are too small. common side effects include people yelling crack attack! small children running away, loss of job, loosing pants, looking ugly.
guy 1 : "dude!, did you see that craction?!?!"
guy 2 : "yeah! ew, crack attack much!"