It isn't a painful red welt any longer, but it will never fully heal either. The off coloured skin still bears the mark of the angel who pulled him from the pit. The angel, who with a look can drop him to his knees and make him beg for release. And there he is, doing just that. Castiel would never have thought it possible that Dean Winchester could so willingly submit to him, but he didn't know then what he knows now. The angel's palm fits over the scarred flesh to cover it completely, sending a shutter through the hunter and a jolt of lust runs up his spine.
Dean is the one who fights, and stubbornly gives orders when they are intimate, but now, with this power in his grip, Cas holds tight to that shoulder he marked with his own flesh so long ago. There is an electricity that flows between them as Castiel uses his free hand to pull Dean's head closer to his hard cock.
Watching as Dean takes him in his mouth without question or rebellion is almost enough to make him cum, but he can't let go yet. There is too much surging between them to have it end so quickly. When at last he loosens his hold and the connection is broken, Dean smiles broadly and says, "Always knew you had it in you, Cas. Don't ever change."