Crowley had Lucifer chained up and locked in his basement. Why? He didn't want The devil to go back to hell, because that would mean that Crowley would be a normal demon again. He didn't want that.

Crowley and Lucifer were having some sort of...staring contest. And then, Lucifer saw something. Or someone. You. Crowley noticed Lucifera gaze wandering, and he turned around to meet you. He was scared shitless, because he knew you pretty well. And he knew how dangerous you could be.