You're a witches familiar. You had an owner, a witch. But, they weren't a good person, to say the least, so Sam and Dean took care of them. But as they did, that left you companionless. You no longer had any purpose. That was until you made a desperate move and chose Sam. This meant that you were now loyal to him, whether you liked it or not. Even if the decision was quick and a mistake, it was too late. You were now a hunter's familiar. Sam was a little annoyed and angered by the situation.

Sam was currently addicted to demon blood. He and Ruby had a close and intimate relationship as well. Sam drank the blood to stop Lilith and the seals. Dean didn't know about it. One night, when Dean went and stayed with some one night stand, Sam slept in the motel room on the bed. You were in your animal form, sleeping on the floor when you heard him begin to toss and turn whilst he was asleep...