Disclaimer: This story does not contain explicit sex, so if that's what you're looking for, this may not be your cup of tea.
Thanks goes to Stella_Omega and Rozezwild for their advice and editing.
Somehow, he had anticipated that knock on the open door. She had gotten into the habit of showing up in his classroom after hours irregularly a long time ago, whenever she could make time to see him, which wasn't often. But somehow, he had felt that this would be one of those days, and his entire body felt lighter in an odd way when he heard the knock.
He smiled, not even looking up from the homework he was grading.
"Am I that predictable?" she inquired, and his smile grew wider as he raised his eyes and allowed himself a long look over the pale, brunette girl that was standing in the doorway, leaning her head against the wall to one side. Sadie was small, but elegant, with high cheekbones and expressive brown eyes that he couldn't stop himself from gazing into for a few seconds. Her slender arms were wrapped around her folder, books and notebook, just like she had always entered his class when she has still been in high school. Her medium brown hair, always completely straight, never pinned up or pulled back, fell an inch or so below her shoulders.
He marveled at how little she had changed in the last few years. She had lost the timid look in her eyes a little bit, college seemed to agree with her in that regard. Her lips also weren't quite as bitten as they used to be, and she had finally gotten rid of the huge baggy sweaters she had used to hide in for so long, and wore a t-shirt that was actually in her size.
"I just had a hunch," he said finally, and Sadie came closer, almost shyly. Things were always awkward between them at first, before they got used to talking as equals again, not as the student and teacher they had used to be. She gave him a small smile and pulled up one of the student chairs with a charring noise that made him grimace. Most of the rubber feet on the chairs in his classroom were broken or gone, a fact he hated, but couldn't change.
He watched as Sadie took a seat. Her small frame still fit into the chair perfectly, just like it had more than four years ago, when she had been in his class. She was the only thirteen-year-old he had ever had in his Calculus class, and he had been fascinated with her and the way her mind worked from the very start. Sadie had breezed through Calculus, but stayed after class often to discuss advanced problems or ideas she'd had with him. He had started to challenge her soon, with everything from tricky integrals to theoretical questions that required a high level of abstract thinking. She rose to each challenge magnificently. Sometimes she would storm into his classroom first thing in the morning, with flushed cheeks and gleaming eyes, to present a solution to him. She had been the most enthusiastic student he had ever taught, by a far stretch.
And she still had her passion, he noticed when she put down the stack in her arms. Atop lay a Linear Algebra textbook, which was pleasure reading for Sadie by now.
"I'll wait if you want to finish this," she offered, flicking her lovely eyes to the homework in front of him. He shook his head and pushed the stack away, focusing his attention on her as she played with the part of her bookmark that stuck out of the book. She looked so young just sitting there that he could hardly believe that she was in her third year of college now. She had had a birthday a month ago, but he wasn't going to congratulate her if she didn't bring it up. It wouldn't feel right admitting that he knew her birth date from the top of his head.
He leaned back in his chair, swivelling it sightly. "How are your classes?" he asked, watching as her face broke into a smile right away.
"Mostly they're really fun, except for Astronomy. I hate having to get up in the middle of the night."
"For Astronomy? Imagine that," he teased her, enjoying her innocently flushed cheeks.
"Differential Equations is my favorite," she changed the subject. "It's easy. I've been looking ahead in the book, mostly at systems and Laplace Transforms, although I don't have a complete grasp of them yet."
"The transforms are difficult to grasp," he agreed. "Especially once you get around to transforming square waves and all kinds of other abominations."
That made her laugh. "Did you have trouble with those when you were in college?"
He looked at her, rubbing his temples. "You're making me feel old, you know. I don't even remember."
"You're not old," she said. Her cheeks flushed slightly as she looked up at him, her eyes darting over his face briefly. "You're not old," she repeated. He gave her a brief, sincere smile and changed the topic.
"How are the other aspects of college? The food?"
"Still horrible," she said without hesitation, making him laugh out loud.
She shrugged. "Nice. My professors are really helpful outside class. I enjoy that."
"How are you getting along... socially, I mean?" he asked her, and the expression on her face changed at once. He hadn't meant to cause her any pain by asking the question, but she had had problems even in high school, and he had been the person she had ended up confiding in.
"It's... it works out," she said reluctantly. He could read in her face that she didn't like lying to him, but she did anyway, maybe out of embarrassment, because she had trouble understanding the people around her. He had noticed a long time ago that she had the social awkwardness that troubled many highly gifted students. Not wanting to be the cause of any more of her discomfort, he changed the topic once more.
"I just remembered, I believe I have a Differential Equations book here that gives examples of some of the more complicated Laplace Transforms. You know, the composites." He stood up from his chair and walked past Sadie to one of the bookshelves where he kept his personal collection of advanced math books. He grabbed a dark green one without hesitating and turned back to the desk, flipping the book open and flying through the pages while standing. Sadie was next to him, very close, watching him flip through the book with interest. Finally, he found what he was looking for.
"Here," he pointed, pushing the book to the side so she could read it over his shoulder. Sadie leaned forward, her hair brushing over his shoulder, and when he took a breath, he could smell her intoxicating scent. She was wearing a bit of perfume, he noted with some surprise.
"That's amazing," Sadie commented on the table he was showing her. "I'm curious about where some of that comes from, I may have to calculate some of the integrals just for fun."
"You would," he laughed.
"I've been out of practice," she admitted and looked at him with a wistful half-smile. "I miss figuring out your integrals and derivatives from hell."
"I miss giving them to you," he answered, watching as her long lashes lowered for a second when she seemed to consider something, then her lovely dark eyes looked into his again.
She kissed him.
He was so unprepared for it, he felt as if in shock. Her lips rested on his for only a few seconds, before she pulled away and took a step back, obviously embarrassed. He promptly missed her physical closeness and her scent.
She didn't run from the room or any such thing. It was Sadie, after all. She simply stood there, fingers knotted nervously, and suffered through the uncomfortable silence while he tried to figure out what the hell to say.
"Babe, I'm two and a half times your age," he finally said softly, closing his eyes for a second and cursing himself silently for calling her by an endearment. She only bit her lip harder, and he saw her eyes narrow as she calculated quickly.
"More like two point four, rounding up."
He couldn't help smiling at this, so very much part of her character, and he stretched out his hand for her to grasp, unable to see her so very much uncomfortable.
"I can't," he said simply when her hand was in his, and she had taken a step towards him.
She cleared her throat. "I'm eighteen."
He nodded. "I know that."
"And you're not my teacher anymore."
He looked at her sharply. "That's not the point."
She took a step back, and her hand slipped from his. She appeared to want to say something as he looked at her apologetically, but her lips wouldn't form the words.
"Sadie," he said, much more softly now, finally getting up from his chair and stepping towards her. His hand seemed to get a life of its own as it rose and ran through Sadie's hair comfortingly. He wished fervently at the moment that she had been born a decade or even two earlier, that this wonderful, brilliant mind wasn't bound to a body that made it wrong for him to even touch her. Not legally wrong, maybe, but morally.
She looked up at him, her eyes sad and disappointed under those long, feathery lashes. She nodded shortly, as if in acceptance, and seemed to consider once more before she lifted her chin, leaned forward and pressed her lips against his once more.
It was supposed to be a good-bye kiss, he knew that. She was planning to leave the room the instant the kiss ended, perhaps never to return. He knew it was the best thing for both of them, but he couldn't help himself as he started to kiss her back, first only returning the soft pressure of her lips, but soon holding her with one hand on her neck and the other on the small of her back. She put both of her arms around his neck, never breaking the kiss, and pressed herself against his body almost enthusiastically.
Finally, after a long time, they pulled apart, and he promptly closed his eyes and leaned his forehead against hers.
"Sadie," he only said, and she kissed him again.
This one was more intense than the previous one, stealing his breath, and her tongue slipped into his mouth after a few seconds or so. He let it happen and only pressed her closer to him while she timidly explored his mouth and toyed with his tongue. It felt good, so incredibly good that he could barely keep himself calm, but he managed, for Sadie's sake.
When they parted this time, he noticed that his arms were shaking. Sadie's breath was accelerated and her cheeks flushed wildly, while her eyes searched for something in his.
He didn't know what to do. He'd never been in a situation like this, doing something that felt so right but that his mind screamed was so wrong at the same time. All he did was hold on to her, kiss her forehead, only to notice the heat in her face was so intense it almost felt as if she had a fever.
He finally forced himself to let go of her for a moment, if only so he could sit back down and motion for Sadie to join him. His arms wrapped themselves around her as she sat in his lap, legs dangling over the armrest of his chair. She was light as a feather. Her lips moved towards his again before he could react, and they kissed some more. He couldn't get enough of the sweet taste of her mouth, and in the end it was him who wouldn't let her break the kiss, who kept her close with one hand while the other held her tightly around the waist. He finally dared to reciprocate the caressing of her tongue with his own, carefully exploring what she let him. Sadie's fingers were digging into the muscles of his shoulder almost painfully while her other hand caressed his cheek and neck, and he pressed her so close he was, for a moment, afraid she couldn't breathe. The smell of her was intoxicating, making his head spin and his mind beg for this never to end.
But it had to end, and they were both gasping for breath when they finally broke apart. Sadie leaned her head against his shoulder and allowed him to look past her, and his chest tightened when he noticed the open door. If anyone came looking for him, just peeking in the room, they would be caught, and he didn't dare even consider what that would do to Sadie's reputation.
"We can't do this here, Sadie," he whispered into her ear, and she nodded in understanding.
"Let's go elsewhere."
"No." He tensed, clinging to the ridiculous hope that he could still control this if it didn't go too far. Sadie didn't reply, but only pressed herself closer to him. His hand rubbed her back comfortingly, and somewhat helplessly.
I don't know what to do, Sadie," he whispered into her hair, clenching his hands into fists. He was the adult, the one who was supposed to have his act together and make responsible decisions. This wasn't responsible. But he couldn't bring himself to tell Sadie this, couldn't bring himself to ask this beautiful, intelligent creature in his lap to leave. It had been too late as soon as he had responded to her kiss.
He cursed himself mentally, for having no backbone, and for not keeping his feelings for Sadie safely inside him like any moral teacher would. None of the accusations he hurled at himself could sway him though, and he kissed her hair again, resigned.
The sound of approaching steps from the hallway made the decision for him. Sadie slid off his lap more quickly than he could react when she heard them, grabbing her books in the process and pressing them close to her chest. He shifted in his chair, uneasy and not liking the feeling of her body moving away from his once again.
"I should –" Sadie's eyes flicked towards the door, and he took a deep breath.
"Yes." It was ridiculously hard for him to say this one word.
Sadie nodded simply, her eyes never leaving his as she started to back toward the door, using her stretched out hand along the wall as a guide. His throat had a lump in it when she had reached the door, and she looked back at him one more time, her dark eyes full of something he mentally refused to interpret. His mouth opened to say something, what, he wasn't quite sure, but it never came out as he simply looked at her, open mouthed and helplessly. And just like that, she was gone, her body vanishing through the frame of the door. The steps out in the hallway had passed his door by now, but he still stared towards it for a very long time.
The next time she came to visit him, he didn't expect her. He hadn't even been sure whether to expect to ever see her again, just like he hadn't been sure if that, in the end, was a good or a bad thing. He had been unconcentrated in the previous few weeks, thinking of her much more often than was good for him. Too often he caught himself picturing her lovely, attentive face looking at him among the front row of students in his class, and even more often he found himself wishing to experience the feeling of her lips against his once more, and the feeling of her slender arms around his neck as he held her. He thought of her during the school day, wishing she would pass him in the hallway with a shy smile like she had done in her high school years. He found his thoughts circling around her at night as well, wondering what it would feel like to have her laying next to him, to have his arms around her and hold her protectively while she slept.
He'd had students with crushes on him before, but he had never reciprocated. And just the same, he had not been able to help a mild sexual interest in some of the senior girls in his classes, but he had always been able to keep that to himself. Now he had acted on it. This was different, it scared him, and he had no clue how to handle it.
He didn't know how to react when he broke his concentration from entering grades and lifted his head to the knock at his door, seeing her there, just like so many times before, leaning against the doorframe. This time though, her dark eyes seemed unsure and worried, as if she wasn't sure she was welcome. His mouth was suddenly dry, and his hands grasped the armrests of his chair tensely as he took a deliberately slow breath.
"Hi," she said, and the one word sent an excited jolt of electricity through him. He remained silent as his eyes locked with hers, trying to read in them and finding just as many conflicting feelings as he knew to be in his own.
"Sadie," he finally whispered, hoarsely, and she flung herself at him.
He barely managed to get up from his chair before her body wrapped itself around his and she kissed him enthusiastically. It took him a few seconds to react at all, so unexpected had her action been, but then his arms closed around her and he responded to the constant caressing of her lips with his own.
"I missed you," she whispered breathlessly, causing him to kiss her even harder and barely finding the time to draw breath. He crushed her against his chest, caressing her back and neck, feeling the heat of her face close to his as she clung to him and continued to make his heart race. The kissing lasted for a long time, as both of them seemed unable to let go of each other.
Finally though, they were completely out of breath and had to pull apart. He rested his forehead against hers and felt her hand stroke his short hair. One strand of her brown hair was stuck to her lips, and he lifted his hand automatically to brush it away. He felt her breath brushing his cheek repeatedly and closed his eyes, enjoying the feeling of being able to hold her close once again.
It took them a few minutes until they both caught their breath and were able to let go of each other enough to look at each other. He took his time taking in her features, her innocently flushed cheeks and lips that were red and moist from kissing, those deep brown eyes and the delicate features that made her face look so elegant.
"I missed you too," he told her, rather belatedly, and her face broke into a wide, beautiful smile.
"I didn't know... I wasn't sure if you wanted me to come back."
He raised his hand and touched her face lightly, tracing her jawline with his thumb. "You're kidding, right?"
"I'm glad," she whispered. He pulled her closer and she rested her head on his chest. Her eyes were closed as they enjoyed their closeness once again, and he tenderly kissed the top of her head as he stroked her hair.
Only then did he notice the backpack she had dropped by the door, and he frowned.
"Sadie," he said, his voice giving away his concern, and she turned in his embrace to look at his face.
"I know," she said simply. "I just had to get away for a while. It's not... it's nothing major. But I didn't want to go home either, and I was hoping... ."
He tensed. "This is not a good idea, Sadie," he told her, taking a deep breath.
Her dark eyes met his, pleading. Making it impossibly hard to decline her.
His mouth was suddenly dry, and he was freshly aware of her small body pressed against him. She was warm and tempting and innocent all at once, and he knew that letting her stay at his house would be a big mistake for both of them.
"Alright," he said, before he even realized that he was thinking the exact opposite.
"Thank you," she said, looking down and leaning her forehead against his chest. He kissed her hair again and sighed. This was just one more item on the list of irresponsible decisions he had made lately. Still, Sadie was eighteen. As much as he still felt responsible for her well-being, he wasn't. Not legally.
He sighed once more and stroked her hair again before pulling back and looking down at his desk.
"Let me just pack my bag. Then we can leave."
"Are you sure you don't want to talk about what happened?" he asked her later, when she was curled up in one corner of his couch, reading a book. Rain was drumming against the windows, creating a rather cozy atmosphere. She looked up and shook her head, flushing slightly. He sat one of the plates he was carrying down on the table in front of her, then sat down on the other end of the couch himself. He didn't want to crowd her, especially with her being so reluctant to confide in him.