"It was not my intention to offend," Cas replied, frowning. "And I'm very familiar with gods. This is not information you need to impart to me, though the advice is very valued."
In a way, Cas found it slightly offensive, but knew better than to react. On any given day, he found many things offensive. Things other humans generally didn't find to be so. His temper was something he still needed to work on. Even if every part of his vessel was urging him to break something. His more rational mind however, told him that Morpheus was undeserving.
"I relinquished my Grace," he explained simply. "It was by choice. While I am not human, I am not what you could consider an angel either."