Summary: After Megan decides to take some classes at CalSci, she finds herself struggling with her physics class and turns to her favorite physics professor for further explanation, which prompts her to ask for a real life demonstration to prove that every action has an equal and opposite reaction. Pure fluff. AU...sorta, but occurs sometime during Season 4.

Pairing: Dr. Larry Fleinhardt/Special Agent Megan Reeves

Rating: T for sexual situations

Disclaimer: I don't own Numb3rs, but if I did, we'd have A LOT more scenes between Larry and Megan.

Reviews/Feedback is very much appreciated!

Megan was pleasantly surprised that Larry was the one who suggested they live together. It had happened somewhat by accident, too. After returning back from her DOJ assignment, her small two-bedroom apartment just hadn't felt like home anymore - it just reminded her of a life she would never be able to return to, a woman she didn't recognize anymore. One day, after visiting CalSci to work on a case and the man who was as lost as she, Larry had mentioned she needed a change in her life. He could see the light in her eyes slowly darken, which he had ironically described as a star collapsing on itself. It had happened. Megan couldn't avoid the truth anymore that she was a changed woman, because if Larry could see it through the fog of his own confusion after space, then there was no way she could avoid it.

She needed a change.

Megan had used her monthly "wild card" to take him house hunting with her, to search for a location more permanent that she could genuinely settle into - and, she'd hopefully admit to herself, that Larry might deem home as well. After an entire half day of searching, she walked into a modest ranch with Larry and her realtor, an elderly woman who had assumed they were a married couple looking for their first house, a mistake which Megan didn't feel was necessary to correct.

The comment had slipped past Larry who, as soon as the woman said it, spotted the master bathroom equipped with a shower and a large bathtub. Somehow, he had restrained himself until the realtor had walked outside to give them time to consider the home. Megan had laughed to see him swing his legs around the porcelain, letting out a happy, contented sigh. Grinning, she walked up behind him, wrapped her arms around him so her hands dangled over his chest, and sighed.

He turned his head so their cheeks met, his stubble gently rubbing against her skin. In a whispered awe, he told her, "This place is perfect for you, Megan."

"Perfect for me?" She chuckled softly, kissing the spot just below his ear that made him tense up. "Or perfect for you?"

"Both," he answered, his voice weak as he fought the urge to slip further into the tub. "It's...It's perfect. Adequate space, a bedroom for guests, a wonderful bathroom and tub."

Megan raised an eyebrow at him and asked, "Will you be one of my guests?"

Larry shrugged. "I wouldn't want to be an imposition." He paused to think for a moment, and realized that living with her, in the same house with a shower and a bathtub, would be better than the monastery in Altadena where he felt like he couldn't think even though that was all he had time for. His transition back to Earth had proven more of a challenge than he had anticipated, but he felt safer in Megan's arms than in the steam tunnels. "Why don't you and I live together?"

"Oh?"

He nodded slowly. "I could...I could stay in the guest bedroom so that we don't get in each other's way."

"Because we all know how unorganized you are," Megan quipped with a smile.

"Hey!" Larry countered, raising a finger at her. "My mess is an organized clutter!"

Megan began to rub lazy circles on his chest as she rested her chin on his shoulder and asked gently, "Larry, when was the last time you had a roommate?"

"College."

She would have laughed if he didn't look so sincere and afraid of her reaction. "Well," she paused momentarily to kiss him on the lips, happy that he no longer hesitated at her kiss but returned it warmly. Megan chuckled softly when she pulled away, only for him to follow and kiss her once more. Running her fingers through his short hair, she commented, "I"m sure you and I will be able to make it work, Larry."

As it turned out, their things had made it into their respective bedrooms, but Larry hadn't spent one night in his. The first night there, he had awoken to the sound of Megan's gentle cry and found her tossing and turning in bed, a nightmare haunting her while she slept. Larry had woken her up, careful so not to scare her, and hadn't been surprised when she pulled him into bed next to her. He hadn't minded, and for the first time since returning to Earth, he had slept peacefully, positive she did, too.

Now, after living together for three months, Megan wasn't surprised to find that Larry didn't even bother entering his bedroom. She found him one evening, late into the night, sitting up in bed and grading papers. Watching him for a distance was her favorite past time, and not because behavioral science was so engrained in her but because Larry's quirks and actions continued to surprise her. She couldn't read him like she read the suspects they arrested, and every time she stared at him, she learned something new that made her fall in love with him even more.

Megan smiled to see his nose crinkle in disdain as he quickly slashed a red mark across the paper in his hands. Tilting her head, she asked him, "Someone not going to be happy with their grade come Monday morning?"

He looked up quickly, and she knew grading bothered him because he didn't even smile at her. In fact, he didn't even hold her gaze as he turned his attention back to the paper and mumbled, "If this student went to lecture, maybe he'd understand the assignment."

"Well, some students attend every lecture and still don't get it."

Larry only snorted slightly in response, tossing the paper aside to start on a new one. "Yeah, well...Those students should seek help if they struggle. That's what office hours are for."

She raised an eyebrow at him and crossed her arms, amused. "And what about the students whose schedule doesn't coincide with the professor?"

Larry shrugged. "Then tutoring, I suppose. I..." He shook his head, flustered, and finally met her gaze even as his reading glasses fell off the bridge of his nose. "Why are you defending this student so vigorously?"

"Well," she touched her chest, "I go to lectures every day but my physics class still confuses me sometimes. And my hours don't mesh with my professors, and tutoring is hard to come by with my work schedule. The only reason why I do so well is because I have you as my own personal tutor."

"Yes," he agreed, understanding her academic situation perfectly given the many nights she had stayed up, frustrated, because of a physics problem that he could solve within seconds, "but...this is different."

"How?"

"This student..." Larry shook his head and waved his hands in the air, clearly upset, "this student just doesn't care about his future! It's not just my class that he's like this, you know."

"You should give him the benefit of the doubt, Larry."

"I will when he attends class," Larry murmured softly, eliciting a small laugh from Megan. He glanced up at her expectantly then frowned again, his brow crinkling as he pondered her original comment. "Are you still struggling in your physics class, Megan?"

"Well, it's not behavioral science, that's for sure."

Larry sighed softly, surveying the mess he had made on the bed. Piles of papers surrounded him, covering more than his side of the bed. He really didn't want to focus on this right now, not when Megan had returned home from work and wanted to relax. He could put this all aside for one night, certain that the students weren't itching to get back papers that half of them nearly failed. Larry glanced up at her again and asked, "Do you need assistance?"

She raised an eyebrow at him. "You want to help me with my physics homework?"

He shrugged. "I assist you with your FBI cases from time to time."

"Well..." Megan pushed herself off the door trim and walked toward the bed, smiling when he quickly shuffled some papers around to give her room. Sitting down on the spot he had cleared, she admitted, "I am having some trouble with this one homework assignment that we received a couple days ago. Would you mind helping me?"

"Of course." He grinned when Megan smiled gratefully and leaned forward to kiss his lips softly. When she pulled away, her lips brushing against his with a gentle hum, he asked, "What's the assignment?"

"I have to find real world applications for some theories and laws we've learned in class," she explained.

"Yes, but what is the law or theory that requires application?"

"Newton's third law of motion." She laughed gently when he snorted in response. "What? That's a hard theory to learn!"

"Every action has an equal and opposite reaction!" He returned, his tone just as flummoxed as hers. He scratched his forehead thoughtfully before reminding her, "That's one of the easiest physics laws to learn! It's self explanatory!"

"Not to me," she answered with a shrug. "I think I might need a demonstration."

Larry simply squinted at her, wondering what game she was playing by the smirk and bright playfulness in her eyes. "A real life demonstration?"

"Sure," Megan agreed happily. "A real demonstration sounds wonderful actually."

Larry huffed as he stood from the bed. Megan grinned to hear him grumble under his breath about Newton's Three Laws and how simple they were to learn, and that she must have had Nielson as her professor if she really couldn't understand them. Shaking her head with a bemused smirk, Megan rose and followed him into the living room and finally the kitchen where he pulled out a spoon.

From the safe distance of the island, she watched as he raised the spoon to gain her attention, then brought it down against the granite countertop gently with a soft clang. Shrugging when he gazed at her expectantly, she asked, "So?"

"The force that the spoon exerts against the granite is the same that the granite exerts on the spoon," Larry explained, as if that clarified everything even though all he really had done was replace words. "So the spoon is Object A in this experiment and the granite countertop is Object B."

Megan nodded her agreement. "Haven't lost me so far."

"Good. Now," He lifted the spoon with one hand and raised a finger of his free hand, "The direction of the force of Object A is opposite that of Object B. So, the direction of the force of the spoon is opposite of that of the granite countertop. In this case, this is an action-reaction pair - like all objects are, really."

"Action-reaction?"

Larry frowned and, exasperated, exclaimed, "What is your professor teaching you?"

"Not much, apparently."

Larry sighed heavily despite her grin and soft snort of laughter, rubbing his temple in frustration and wondering why she just didn't take his introduction to physics course. If it wasn't for the school's rule that students and professors were not allowed to date, he was certain she would have taken his class, and then this wouldn't have been a problem. He breathed in and out once to collect himself, a technique he had learned from the monks, before he explained, "Action-reaction pairs are when an action by an object exerts a force on another object, therefore creating a reaction. You can have two type of contact interactions, and those-"

"Are contact and action at a distance?" Megan finished for him, smiling proudly when he nodded his agreement. "And contact interactions are normal, frictional, tensional, and applied, right?"

"That's correct. And action at a distance are gravitational, electrical, and magnetic forces." He waved his hand through the air like a fly was buzzing around him. "But we aren't worried about those now."

"Okay," Megan agreed with a nod. "That's good. Because Dr. Nielson explained those in class already."

Larry snorted again. "I'm glad he explained something."

Megan shook her head. "You don't like your colleague very much, do you?" When his face only scrunched up again, she laughed and walked over to him. His body tensed at her close proximity, something she thought would change given the progression of their relationship, but she gave him a warm smile anyway as she took the spoon and set it down on the counter. Her body close to his, the only thing that kept them apart a simple pull of an arm, she told him, "I don't think I'm getting this, Larry."

He frowned. "I don't appreciate your dishonesty, Megan."

Holding back her laugh, she offered, "Why don't you explain a real world application that applies to my life? Say something to do with my FBI training?"

Larry sighed heavily, took a step back, and brought his arms together like he was about to fire a handgun. He tried to not aim his imaginary weapon at her for fear of startling her, but she only stared at him amusedly. "So you're firing a weapon right?"

"I don't have to fire my weapon all the time, Larry."

Larry shook his head at her response and continued, "When you fire the weapon, your arms fly backwards correct?"

"If you don't have a firm grip, yes," Megan answered, remembering when she had first fired a weapon and the force of the shot was enough to send her toppling backwards because she had been unprepared for it. Larry, however, only stared at her with wide, open eyes. "But, I get what you're saying. The gun exerts the same force firing the weapon as it does propelling back toward me, and the forces are opposite."

Larry nodded happily. "So you understand a real life application for Newton's Third Law?"

"No."

Megan smiled slightly when he groaned heavily in exasperation and fell backward, his body twisting in what she could only describe as a physical manifestation of a whine. Before he could give a response, she took a careful step forward and wrapped her arms around his neck, pulling his body against hers so the only distance between them was that which their lips had yet to bridge. Gently, she placed a swift kiss on his lips and commented, "I think I found a real world application I might understand."

His fingers feathered down her arms until he gently held her waist. "And what is that?"

Megan only smiled before she kissed him again, eager and hungry. The ferocity of her kiss must have caught him off guard because he tensed against her, but within seconds he matched the intensity of her kiss with his own. She pulled away only to breathe, and smiled when he moaned softly in protest, leaning forward to kiss her again. She stopped him, however, with a gentle hand against his chest, and told him, "Every action has an equal and opposite reaction, right?"

Larry nodded his assent slowly before tucking his head to place feather-light kisses on her jawline, smiling to himself when her head tilted slightly to allow him better access. Once he had hit the spot just below her ear that sent her arching toward him, he asked, "Do you understand now?"

Her only response was a soft hum and burrow of her fingers in his short curls. When he pulled away from her neck to gently kiss her lips, she answered, "I think I might need a more...in depth demonstration."

"And what contact interaction would this demonstration prove?"

"Friction," she responded happily, her lips meeting his again. "I know I'll get that one right every time."

"Well then..." He took her hand gently in his and pulled her away from the island, out of the kitchen, and toward their bedroom. "Let's go see if you'll pass the test."

"And if I don't?"

"We'll have to retry the demonstration as many times as necessary until you understand," Larry answered simply, returning Megan's smile as he pulled her into the bedroom.

They could both agree that this was arguably the best physics lesson either of them would ever have.