Normal POV
Derek heard the door slam and jolted up. He looked over at the door and saw Casey walk in.
"How was your date with Sammy- Boy?' Derek says, but gets no response. "Casey?" She just takes off her coat and backpack. He gets up and walks over to her. When he sees her, he looks at her eyes and sees that they are red and swollen and it looks like she has been crying. "Casey?" He asks softly. He looks, concerned, at her. She just walks upstairs. He follows her upstairs to her room, where the door is shut. He knocks on the door, but gets no answer, so just walks in.
"Go away." He hears a muffled response from Casey with her head in her pillow.
"No. What happened? What's wrong?" He asks softly and sits next to her on her bed.
"Why do you care? You hate me" She says while sniffling and obviously crying.
"I don't hate you. You come into the house crying, so of course I care. C'mon, just tell me what happened Casey. You're scaring me. What's wrong?"
She sits up in the bed next to Derek and wipes her eyes. " H-he ch-cheated on m-me." She says as she puts her head into her hands and starts to cry again. Derek looks at her sympathetically.
"Sam cheated on you?" She just nods in response. "Casey, he doesn't deserve your tears, don't cry." She just cries even harder. Derek pulls her into a hug and he sits there rubbing her back and saying comforting things. Eventually she calms down a little.
"Isn't this what you wanted, Derek? You never wanted us to be together. You must be so happy now." She says teary-eyed.
"No, I didn't want you guys together, but I'm not happy. He hurt you." He says
"Why do you care? I'm just your annoying stepsister that you hate." She replies.
He looks at her and then looks down, " Casey, I don't hate you. You're my stepsister. I don't want to see you hurt. I'd rather have you guys together, than you sitting here crying because Sam was an idiot. I care about you like a sister. Anyone who hurts you, gets hurt" He says and chuckles lightly to try to lighten the mood a little.
She just nods. "You know you don't have to sit here with me. Don't you have dates to go on or something?" She says and then sniffles.
"Casey, I'm not going anywhere. I'll sit here as long as you want me to. I'm here for you." The way he said that almost brought more tears to Casey's eyes but in a good way. "Look, I'll be right back. I have something to do." Casey could tell that he was angry and he looked like he was going on a mission. She knew he was going to go to Sam. She needed him, though.
As he was walking out of the room he heard, "Derek? Um, do you have to go? Cuz, um, I was just wondering if you could stay here with me. I don't want to be alone."
He looks over at her and says, "Of course. It can wait Casey. I'm here for you." As soon as he says that she breaks down crying again. He rushes to her side and pulls her into another hug. She hugs him back as hard as she can "It's going to be alright Casey don't worry." He says. It was getting late, so he laid her down and they laid together. She cried and hugged Derek as tight as she could as if it were for dear life and Derek was hugging her back saying comforting words and rubbing her back again. They eventually fell asleep in each others arms.