A/N: Oh, I know that this girl is probably a Mary Sue, but honestly I don't care. People tell me that all my OC's are Mary Sue's so I've accepted it

As James Potters little sister, Chelsea knew she was not to associate herself with his friends in public. That was the code of little sisterhood. But James wouldn't have it. He adored his little sister. Unlike most older brothers, he was able to see that she wasn't too different from him and his friends other than her gender and one year age difference. In fact, he knew that if she were in the same year she would definitely be in their friend group.

"Hello Chels."

And then there was Sirius. He just so happened to be the main reason Chelsea did not hang around with her brother and his friends. She may or may not had started to develop feelings for the shaggy haired flirt since she was thirteen. Now she was fifteen and he was sixteen. Though she did her best to avoid him causally, there was always the common room. Every night she was one of the last people to leave. And every night Sirius would sneak out of his room and sit down on the couch next to her.

She looked at him as he flopped down next to her, his arms slung around the back of the sofa. God he was attractive. "Hey."

"What are you reading." He looked over her shoulder, his torso pressed against the side of her arm.

Chelsea's heart beat began to pick up, feeling the heat from his body mixing in with hers. "Oh just a potions book." Sirius closed the book and tossed it onto the coffee table in front of them. "Hey, I was reading that."

He smirked a bit, "And now you're not."

Rolling her eyes, she leaned back against the sofa and looked at him exasperatedly. "Why do you need my attention so badly right now?"

"I always need your attention." Sirius said simply. Her stomach erupted in butterflies at his response. She was so flustered she was afraid to respond. Thankfully he didn't give her much of a chance. "Close your eyes."

She swallowed away her nervousness, or at least tried to. "Why?"

He smiled at her softly, "Please?"

Chelsea sighed and did as she was told to, fluttering her eyelids shut. Why on earth is he making me do this, she thought, what could he possibly be up to? She jumped a bit when she suddenly felt something press against her lips. Oh my fuck is he kissing me? Sure enough, when she reached her hand out she felt his face so close to hers the only thing he could be doing was kissing her. Her arms wrapped around his neck, securing him so he couldn't move. Sirius smiled into the kiss.

"James is going to kill me." He mumbled against her lips.

She smirked a bit, "In that case why don't we go somewhere where we won't get caught."

Sirius eagerly pulled away and took her hand, leading her out of the common room and to the hallways of Hogwarts. After searching for a spot for a bit, they found an empty broom closet. He opened the door and gently pulled her inside the small space. Between how small the room already was and the shelves on the walls, they had no choice but to be tightly pressed against each other. Not that they particularly minded though. Once in the closet he held her waist in his hands and rested his forehead against hers.

"Can I tell you something?" He asked, his voice slightly nervous sounding.

She smiled, "You can tell me anything."

Sirius hid his face in her neck, incasing her in his arms. A small sigh escaped his lips and brushed on the skin of her neck, making her shiver at the sudden warmth. "I love you."

Chelsea smiled, wrapping her arms around his neck. "I love you too."

With a wide smile on his face he picked her up by her waist and spun her around. Keeping her in the air, he pressed his lips against hers again. Not as gently as the first time, but much happier. Slowly, he eased her back down to her feet, his lips still connected with hers. Chelsea pulled away from the kiss so she could tackle him in a hug that sent him pressed against the wall.

He smirked at her a bit, "Seems that someone wants a bit more than a kiss, eh?"

She rolled her eyes, "You're saying that because you're the one that wants more."

Sirius leaned in so his lips were only brushing against hers, "How could I not?" He asked, his voice just a little bit husky. "You're perfect." Seeing blush begin to make it's way on her cheeks, his lips connected with her neck.

Chelsea tilted her head back a bit so he had better access to the sensitive skin. She bit her lip so she wouldn't let out the moan she was holding back. At least for the time being. He held her waist tightly against his body, expertly kissing her neck as he did. Her eyes fluttered shut when he continuously kissed the same spot, then began to bite it softly.

"I don't want my first time to be in a broom closet, Sirius." She managed to say without moaning.

She felt him smirk, "So you're saying you're going to have your first time?"

"Shut up and take me somewhere else."

After leaving a mark on her skin he opened the door and led her to what he called the room of requirement. Inside the room which formed after they stood there for a few moments was practically the same set up as the Gryfindor common room. The two teens sat on the floor in front of the fire and stayed up talking and kissing all night. It was perfect. And in his own way, he was perfect. At least to her.