This is a small idea I had...that grew a lot.
Disclaimer: I own no Supernatural people. Which makes me sad.
It started out as an innocent request from his sister.
As most life changing and ridiculous things start from his siblings.
"Help me write a love letter!" Anna had practically yelled as she entered his room. Without knocking.
"What?"
"A love letter. To Balthazar. Write it for me. Please?" she begged. Actually getting on her knees right next to Cas as he sat in his desk chair attempting homework.
"Why not write it yourself? You are the one feeling the emotion. It would be simpler for you to do it." Cas explained turning back around to focus on his math.
"You're the good writer." Anna whined. "You write short stories all the time and you read. A lot."
"I've yet to be in love, Anna. I wouldn't know what to put." Cas attempts again.
"But the thing with Meg?"
"A crush. Nothing more."
It got silent. Cas was doing his math and waiting for whatever his sister was gonna bribe with to do this.
"10 bucks."
"No."
"15?"
"Anna-"
"20!"
"Would you-"
"25! Final offer."
"I'm not going to take your money." Cas sighed finally looking at his sister.
"Please, Cas? I'm desperate." Anna whispered looking up at him, still on the ground.
"Fine." Cas sighed.
He had to cover his ears from his squeals of delight. And thanks.
"Thank you! Thank you! Thank you!" She said jumping up and squeezing the air out of him.
"Give me a while." Cas said turning back to his work.
"Sure, sure. Take all the time you need." She replied.
Cas thought she'd leave the room and forget all about this the next morning.
Except, she was sitting on his bed. Watching him.
"Now?" Cas asked exasperated.
"Sooner it is, the less time I'll bother you about it being ready." Anna explained with a smile.
Cas sighed. He got quiet to think of a plan of attack.
He grabbed a near by, small notebook and opened it to the first empty page, and grabbed a pen.
He turned to his sister and looked right at her. "Tell me, in your own words, why you love him." Cas said.
"Huh?"
"This is a personal love letter." Cas explained expecting this reaction. "I can't just make up feelings and quirks that you find "adorable"." He did the airquotes with his hands. "I want to know why you like him the best. What makes him better than the others. What attracted you to him. You explain these thoughts and answers to me and I'll make them sound...eloquent." Cas said for lack of a better word.
"So, I explain why I like him, and what I like about him and you'll make it sound pretty?"
"Basically."
"Alright. " Anna said. Then she blushed. "It's a bit odd talking to you about this."
"Just...don't make it sound-"
"Final?"
"Yes. If you were bragging to Tessa or someone about him like I'm sure you do at lunch some days. I'll make it sound final." Cas said trying to help her out.
"Yeah! I can do that." Anna said, suddenly excited.
Cas was grateful for the quiet that enveloped the room as his sister was thinking of the situation.
Don't get him wrong. He loves Anna, just as he loves Gabriel. But he does like having a small break between Gabriel teasing him at school and Anna coming to him with the latest gossip about most of the people who aren't aware he exist. Which is usually for homework, but he does enjoy it greatly either way.
"Well," Anna started, "he knows the best place to get wine despite being underaged?"
"Anna."
"I'm trying." Anna said, leaning down on the bed sighing. She started talking to the ceiling as she continued. "His smile is beautiful. Just seeing it makes my whole day." Cas could tell she was smiling from her voice. "He pretends to be a man-slut. I've overheard him with his soccer buddies bragging about bedding a girl from another school. But later, he punched the crap out of Zach cause he was forcing himself on a girl at a party. Balthazar comforted her. Nothing sexual, just sweet and comforting."
Cas writes every word out of Anna's mouth, remembering Zach getting expelled, the news and stories were different each time he heard them though.
Anna sits up and continues talking. "Whenever I'm feeling down, he gives me one of those little white, round flowers that grow everywhere. And when we talk, we never seem to have a problem starting or even continuing a conversation. It's the ending we have problems with. And on my end, it's because I want to continue it and stay just a little longer with him. I sorta think, or I hope, it's the same with him." Anna continued.
She kept saying little things about him that she liked, while Cas listened and wrote them all down.
This went on for about a half an hour before Cas had to insist on a pause.
"Hand Cramp." Cas explained flexing his hand.
"Oh, right." Anna said as the dreamy look she had on slowly disappeared as she realized what was happening around her. Her face grew as red as her hair.
"That should be enough." Cas said and he started massaging his hand. "I'll start after I finish my homework."
"Homework!?" Anna yelled standing up
Cas rolled his eyes. "Let me guess. You came here straight after your club."
"Shit!" was his answer as Anna ran out of his room.
Cas was working his wrist thinking of how much his sister explained to him today. He had a small smile as he continued his homework.
A couple days later he had finished the letter. And he had handed it to Anna to see if it was what she wanted. So she was reading it. A loud.
"...Awaiting your answer, Anna Milton." She finished.
"Was that satis-Offph"
Cas was surprised by his sister's hug. She had practically leapt from her spot on the edge of his bed and onto him.
She pulled away with tears in her eyes. "This is beautiful, Castiel. Thank you."
"No problem Anna." Cas said patting his sister's back.
Gabe had walked in on the touching hug.
"Seriously? All deep moving, and emotional hugs have to have me We've been over this." Gabe said joining in on the now family hug.
It lasted a few more seconds until they all pulled back.
"Whats with the hug?" Gabe asked.
"He finished the letter!" Anna said excitedly.
"You guys were serious about that?" Gabe asked looking at them both.
"Yes." Cas replied.
"And its beautiful and lovely." Anna said smugly.
"Good. Now you just have to give it to him." Gabe said as they all headed downstairs to head to school.
Anna froze on the stairs.
"Give it to him." Anna repeated, clutching her bag strap so she didn't harm the letter.
"Yeah." Gabe said looking at her.
"Right." Anna said trailing off
"We're going to be late." Cas said looking at her.
"I don't think I can." Anna finally said.
"What?" Cas asked.
"What if he says no? What if he doesn't even know who I am?" Then she gasped loudly. "What if he likes other hes?"
"Then you apologize to him, hang out with him, and before you know it, you'll have a Will to your Grace." Gabe said grabbing one of her wrists and dragging her down the last few steps and out the door.
"But-but-but-"
"No buts." Cas said, stopping Gabe from dragging her out the door and looked at her. "You came to your younger brother for help and paid him the money that you were saving for the paint set you've had your heart set on. If he's worth all that, then you can at least give him the letter that explains all that to him."
Anna stared at him for a few seconds, then nodded. "You're right."
"Glad that's settled." Gabe said. "But we're late so let's get this show on the road!"
Later that day, Cas was at his locker when Anna found him. She hugged him and told him she had a date that weekend.
So, I have a couple of chapters wrote up. Just have to type. Please R&R, yes?