Warning: Dean and Sam are about to have a fight, the biggest they've had in years, but I promise there's a good reason for this fight, and I was trying to show things aren't shiny, beautiful perfect. I also wrote this before the Season Finale, so it might seem strange for them to fight like this. Bear with me.
Sam looked at Dean, and they were both quiet for several seconds before Dean spoke again.
"How could Lilith have any children? She's a Demon."
Cas lifted his eyes to Sam's, and the younger Winchester...