Dean comes back from a supply run to find Castiel sitting on Sam's bed, looking at Sam's computer.

"Where's Sam?"

"Bathroom," Cas says, without looking up.

"What are you reading?"

"This is very interesting. Dean, I was not aware that human males were able to bear children."

"What?" He's across the room in a flash, staring past the angel at the screen. It's the fanfiction site based on Chuck's books. Dean's seen these stories before. In the beginning, he and Sam were offended by them, but lately they've been more amusing than offensive.

Except that he didn't know the writers were now writing Dean/Castiel slash.

And Cas has no idea what fiction is.

"Cas," he says, "we need to talk."