This may occur in their angelic forms, or while occupying their Vessels - Sam and Dean (their destinted Vessels) or Nick, Adam and Young John (their more well known Vessels). Either way, its another incestuous pairing for the fandom! Most of the slashers of this pairing surfaced after episode 5:13 "The Song Remains the Same" Where Dean told Michael "You know, my brother, I practically raised him. I took care of him in a way most people could never understand, and I still love him."
- Lucifer/Michael comm on LJ. It's tagline is: "Blinded by our pride."