Chuck really wishes he could unsee his last vision about Sam & Dean. A lot. But what has been seen cannot be unseen & Sam & Dean are left to deal with the fall-out of their forever changed relationship. S5, Sam/Dean

Demon!Dean putting up the middle finger to sorrow, guilt and basic manners in favour of sick jokes and hedonism. His filthy mouth is making Cas flustered and Sam's going to start leaving him in a demon trap if he can't keep his hands to himself. Spoilers for 9x23