Castiel tried to find something in Crowley’s words or tone that would tell him something concrete, something he could believe, something that would make Dean’s trust in him more understandable. He listened, but it was easier with something else to focus on. He eyed the cup of tea curiously, taking in the soft scent of it. He put the marshmallow in his mouth, chewing slowly. Sucrose, sodium chloride, starch, fructose, gelatin. Familiar. Soothing. There wasn't a clear answer in Crowley's explanation, but... perhaps clarity was too much to hope for.
Crowley's offer of information, on the other hand... Castiel shook his head as he selected a new marshmallow, hesitant to meet Crowley's gaze. "I've been content with what Dean chooses to tell me... but..."
But now that Crowley pointed it out, it was true that Dean had been keeping things from him. Bad things. The kind of things that had led to Dean coming here. How much of it was because of him? He'd thought, from the desperate longing and relief on Dean's face whenever he looked at Castiel, that whatever had occurred in the future, that future him had been forgiven. Even Crowley, right now, spoke as if he'd redeemed himself in the future. But Dean also hid so much from him.
Suddenly, he thought of Dean in Lisa Braeden’s yard. Castiel had turned to the same demon that sat across from him now, wanting to protect Dean by keeping secrets from him. What if Dean was making the same mistake that Castiel had then?
He turned the marshmallow over in his fingers, stared hard at the worn tabletop, at Crowley's coffee cup, at anything but Crowley's face. "What happened with Lucifer?" he asked, throat dry. "He was in the Cage. What did your death have to do with him?"