Sastiel, Cas tries to feed Sam like a mother bird does.
It all goes to hell - not literally, because with their lives, they usually have to specify - after Castiel watches a pretty boring documentary about birds at the Discovery Channel while Sam is sleeping (and Sam said no staring while sleeping. He called it "creepy”. So unfair. Castiel read this book ‘Twilight’ to learn things about human love and the dude would always stare at the girl when she was sleeping. She did’t found it creepy. Castiel would never trust in Twilight again).
So, of course Cas had to do something while Sam was asleep. And that’s how he ended watching TV. He learned about birds and how a mother bird would feed her babies to show them love and protection.
Then he watched two hours of infomercials.
The next morning Cas tried to show Sam love and protection. It didn’t go well. Sam freaked out and Dean laughed so hard he almost fell from his chair. Sam punched his brother and explained Castiel why he should never try to feed him like that.
Cas would never trust in Twilight or Discovery Channel again.