You're a demon. Dean had died, and Sam was vulnerable, so Ruby swept in. You knew about Ruby and Lilith's plan to manipulate Sam. You were part of it. You helped with everything. Ruby had been sleeping with Sam. You stayed out of that, but you always hated the idea of her with him. When Dean came back from hell, he found out about you and Ruby being with Sam the entire four months he was dead. Dean didn't trust either of you. As time went on... you started to feel... guilty. This was odd. You weren't supposed to have emotion. You were the embodiment of death and destruction.

One night, Ruby sent you to give Sam his fill on demon blood. You met him at night, outside of an old motel he was staying out. He was antsy and twitchy as you approached him with the flask of demon blood, which struck something within you. When he tried to grab the flask, you pulled it back and out of his reach...