Making out with YED.
In her father's meatsuit.
I'm going to be showering for days.
Dean jumps out of the car. He cocks the Colt and trains it on YED, who exorcises himself from Grandpa Samuel's dead body. His black spirit rushes out into the dark night. Dean looks over at Mary in horror and disbelief. Mary looks back at him -- guilty, pathetic, broken. Dean lowers the gun (which we lose track of from here on out) and his face softens, because he knows all too well the bargain she made, why she made it, and why she couldn't refuse, couldn't resist.
Thou shalt have none other gods before me... Thou shalt not bow down thyself unto them, nor serve them: for I the LORD thy God am a jealous God, visiting the iniquity of the fathers upon the children unto the third and fourth generation of them that hate me, and shewing mercy unto thousands of them that love me and keep my commandments.