Cas approached Sam carefully. The younger Winchester was seated at the table, deeply engrossed in a lore book.
"Sam? May I speak with you?" Cas asked.
Sam looked up, surprised. His expression quickly changed to a small smile. "Of course."
"I…believe I have found a way to help you."
"Help me with what?" Sam asked, his brow furrowing slightly.
Cas gathered his courage for what he needed to say next. He'd planned it all out, and created a case based on logic and reason. Now that he was speaking to Sam, his confidence wavered.
"I believe I can cure your addiction to demon blood permanently."
Sam sat up straighter, blinking. "W-what? Cas, how?"
Cas rubbed the back of his neck nervously. "By drinking my blood."
"What! Cas-"
"It is logical. I am the inverse of demons. So my blood should be able to cleanse the demonic taint-"
"Taint?" Sam interrupted, looking hurt. "That's what you still think of me? An abomination?"
"No. I have gotten to know you, Sam, and you are…you are not an abomination. You are…" Cas broke off, unable to find the correct words to convey how he felt about Sam. Amazing and wonderful were not sufficient. No words were.
"No, Cas, I won't drink your blood," Sam said quietly and closed his book, standing.
"Sam, please, let me-" Cas begged.
"No!" Sam shouted. Cas flinched and immediately Sam's expression softened. "Cas, I'm sorry, I-"
"You do not trust me," Cas said quietly, pain forming in his chest and overwhelming him. He understood though. He had done unspeakable things in the past to hurt Sam. It was not surprising that Sam was saying no.
"What? Why would you say that?"
"You willingly drank Ruby's blood. You…enjoyed…the act. You were willing to do that with her, but you refuse with me."
Sam looked away and was silent for a few minutes. "You never saw me like that."
"I have seen you in the depths of your addiction, Sam," Cas reminded him.
"Not like that! You never saw th-those intimate… I never want to be like that with you."
Sam's words felt like the stab of an angel blade. He was unworthy. "I understand."
"You don't! What I mean is, I am not the same person. That version of me was my worst."
"I do not mind you at your worst. I wish to help you."
Sam looked like he was struggling to not be emotional. He shook his head. "I need to be a better person with you. And I need to know that I can do it on my own. That I'm strong enough."
"You are one of the strongest humans I have ever met," Cas said honestly.
Sam gave a small smile. "Thank you."
"So your decision is because of what you need to be. Not because I-"
"No! Whatever you're about to say, no. It has nothing-well, maybe one thing to do with you," Sam admitted.
Cas eyed Sam warily. "What?"
"You're not a juice box, Cas."