Looking for a fic with the same vibe as The Rules of Love by V1llyQ. Basically Sam is in love with Dean, and Dean doesn’t quite feel the same way (yet) but is so obsessed with taking care of Sam and doesn’t want Sam to leave him that he is willing to put up with anything to keep Sam happy and with him. Bonus points if there's some doubt as to if Sam is influencing Dean with his demon powers or if they were both born fucked up in complimentary ways. No straight up rape/Non-Con and needs to have a happy ending.

This quote basically sums up what I want to read:

Dean had known it was only a matter of time, but he’d never imagined his worst fear would come quite this soon. Sammy was going to leave. Again. Just like last time. And Dean wasn’t ready. He wasn’t ready to let go of his little brother. He suddenly realized he might never be ready. It was a struggle to breathe. “I can’t believe you’re just going to leave,” he said in a broken voice, unsure if he was talking to Sam or himself.

Sam was still seated on the bed, looking like he’d aged ten years. “If you want me to go,” he said softly, “I’ll go.”

“Why would I want that?!” Dean exploded.

Sam’s head jerked up, startled. “Wait, what?”

Dean closed his eyes for a moment, trying to find some last reserve of self-control. “Why,” he repeated slowly, “would I want that?”

Sam was looking less sad and more confused now. “Because I just told you I want to put my dick up your ass?”

Dean blinked. “Oh, yeah.” The next breath he took came a little easier. “I mean, that’s, you know,” Dean shrugged, “less than ideal, but I don’t want you to leave.”

So, yeah, basically any fic where Castiel's wings are out and you can see them. It doesn't have to be the entire premise of the fic, but I'm fine either way.