At times, Castiel felt guilty, especially when Sam smiled at him, but the moment quickly passed.
Not having a soul, the angel didn't have a conscience either, so other than a manifest recognition of the wrong he'd done the younger Winchester, pulling his body from the Cage without his soul, not answering Soulless Sam's prayers when he called to him, and not telling Dean his beloved brother was back on Earth, Castiel's remorse stopped there.
He knew Dean had been howling mad at him for breaking Sam's wall and would happily have transfixed him with an angel blade back then, but it seemed Dean had put any idea of vengeance to the side, at least for now.
This made Castiel content.
Because of all the bad decisions he'd made, he really had no-one else to turn to. The 'mud-monkey' humans forgave where other beings never would.
:
However, who could tell what the future might bring?
Neither Winchester was aware he'd been the one to open the panic room door, allowing Sam to go free. Sometimes it was the last straw which broke the camel's back and Castiel knew if Dean turned against him, he was dog-meat. Elimination would come with no delay.
:
He watched fixedly as the brothers joked and baited each other, accompanied by smiles and bitch-faces. He'd never be part of that, the Winchesters saw only each other.
But even without a soul, he felt envy.