Sometimes Dean does or says things that make it sound like he doesn't appreciate or understand what Castiel does and has done for him. Or that what he's done isn't enough.
And sometimes Cas gets a tad frustrated with this attitude.
"I gave EVERYTHING for you, and this is what you give to me?"
Dean and Castiel from Supernatural.
Wig styled by me, outfit not made by me, but I painted the Gryiffindor stripes :3