You are the one with the mark, not Dean.

Not like you wanted to have it, but you knew that Dean was already unestable enough to hold it so, you took it instead of him. You disappeared for 6 months with the first sword and Crowley.. Well, he was the one to transform you into a "demon", to say so, and you now lived in a room on a bar with him. It was like life gave you a break, finally, but you still found yourself craving for killing with the sword.

Crowley had send you demon's for you to kill, obviously, you didn't know that, but it was working for now, since your "murder" addiction was getting into you. You found yourself wrapped into the sheets of your bed, having a [gender of hook up] dressing up again to leave, that was until Crowley entered your shared room, wanting to go and pass the night on the bar once again.. That was until he saw you on his bed.

' Really, in my bed? '

Crowley raised an eyebrow.. Well, you hooked up with someone on his bed.. That was because you knew it or because you didn't, both would be true.