Cas, I'm sorry... [CastielXReader]

Cas Why? (edited)

"We're in the bunker alone for a while, (Y/N). We should talk." Castiel said from the chair he was sitting in. He was at the end of the table, myself across him.
"About what? I don't see the point in socializing when there is nothing I really want to say to you." I say, looking at my book the entire time. At this point, ancient gods were more interesting than a rebellious angel trying to be God.
"How are you feeling, (Y/N)?"
"I'm fine, Cas."
"Define fine for me." I look up from my book to look at Cas.
"Look, Castiel. I get that you're trying to help, but there's nothing you can help with."
"I can listen." He says as if that's the only thing needed. "The best thing someone can do is listen." He continues.
"You really want to know, don't you?" I ask him.
"I wouldn't have asked if I didn't." He says blatantly.
"I'm hurt. Or sad, or depressed, choose one. I'm all of them. I'm completely ready to die; I want to die. I made a deal with a demon which has been canceled, meaning Morgan still has a chance of going to hell. The last of my family is dead. My best friend is dead. I'm hanging with three people- two people and an angel- I don't even know. They try to help but they can't. They won't stop asking. The dog is going to die with me. And I'm determined to stay fine, determined to make myself think I'm fine." I say before sighing and closing the book. JD jumps into my lap and curls into a ball.
"(Y/N), they're your brothers. After the incident of your birth, John left you with your mom and her brother. The story you know isn't real. Morgan knew this. I believe that's why she got herself killed when Sam and Dean came."
"Castiel, no. She wouldn't have done that. If they were my brothers, they would have treated me like it. Years ago, not now. Cas, I've learned in my eighteen years that family doesn't have to begin with blood. It has to begin with care. Family is going to care about you, love you and protect you through anything you go through. People always say that's just being a good friend. In order to be family, you have to stay by someone through it all. She knew all of this. I guess that's why Morgan and I were always considered family." I say the last sentence quieter than the rest. There is a small silence before Cas breaks it. 
"(Y/N), they didn't know. If you want them to, tell them, though they may not react the way you want them to." He says sternly. He picks my phone up off the table.
"Cas, that's the problem. If they didn't know, how are they going to believe me? If you haven't realized, John is in hell and can't really explain things to them anymore."
"(Y/N), tell them." Cas holds my phone out to me. I hesitate to, but I grab the phone and call Sam.
"Hey (Y/N)." He answers the call on the second ring.
"We need to talk." I say, putting the phone on speaker.
"Sure, Dean and I will be back at the bunker in a few days hopefully." Cas wills me to go on.
"No. We need to talk, now." I correct.
"Oh, sure. What's wrong?" Sam asks.
"Sam, I'm your sister." I say.
"Well, yea. You're sticking with Dean and I. We consider you family." Sam replies.
"No, Sam, that's not what I mean. I mean, I'm your sister. Your biological sister."
"(Y/N), what are you talking about?" Dean asks, worried.
"Hey Dean." I say.
"(Y/N), answer the question." Sam says.
"John Winchester. He got my mother pregnant, but left me with my mom and her brother as my family after I was born." I say.
"They said something about wanting a better life for her, but her mother kept hunting." Cas pitches in.
"Wait, John had four kids?" Sam asks.
"Adam is still in Hell, yes." I answer.
"How do you know about Adam?" Sam asks again.
"I knew Adam. We talk on the phone for a few years. Then he stopped calling. Bobby told me what happened. I called him earlier, asked a few things about the Winchesters." I say.
"Okay, now you're for sure sticking with us. Have you met either Lucifer or Micheal?" Dean asks.
"No, why?"
"They must have picked the older ones first." Sam says away from the microphone.
"No, Lucifer went to (y/n), they both did, but Morgan never left her side. (Y/n) was actually the perfect vessel for both of them, but they couldn't have talked to her without being trapped. Morgan was protecting her." Cas says. I look at him confused.
"Okay, thanks for the heads up I guess, but we'll call if anything comes up." Dean says.
"Bye Deano. Bye Sammy." I say. I hang up before putting my phone down on the table. I look down at my hands.
"Lucifer came to me? Michael did? What?" I ask more to myself then to Cas.
"(Y/N), Morgan really did save you. Over and over again. And she would have continued to do so." Cas says.
"Yea." I say. There is more silence. I look down at my hands. 
"Come here." Cas says, motioning for me to go to him. I get up and walk to him, him standing up and hugging me. He held me there for a while, neither of us moving. We stayed like that until I pulled away.
"Cas, what are we?"
"I'm assuming you don't mean physically." He says.
"No, Cas. What are we?" I asked again.
"We are whatever you want us to be." Cas replied.
"Cas, why?" I ask.
"Over the years, I've seen how much you get hurt. Every time, I wanted to save you. I didn't because Morgan always did. I just want to protect you." For a moment, I thought. 
"Cas, I love you." I blurted out. 
"I love you, (Y/N)."

Note: edited.