Dean left Sam alone and went outside of the motel room. Cas was standing there, looking into nowhere.
"Hey... how are you feeling?"
Cas hesitated a little bit. He actually had to think about it, before he answered, "I am... tired. And scared. And angry. Angels shouldn't feel these things."
"Yeah, those are the perks of having a free will." said Dean sarcastically. Cas turned his head and looked at Dean, "Yes" he said slowly.
"Wait... do you regret it Cas? That you ...disobeyed God?" Cas thought about it, and then, still slowly, said: "No. If I had to, I would do it again. I just don't know... if it was right."
"Look, Cas. Your father...God... he told you to love humans, right? And that is exactly what you are doing." silence "But you can't love without being tired, scared or angry."