title: number theory
fandom: Free!
characters/pairings: Nagisa/Rei, Rei's family
rating: G
warnings: kissing, cake, hair getting mussed up
summary: Rei's brother is coming home, and Rei tries to keep Nagisa away
notes: inspired, a bit, by the double Rei's in Lumiose City in Pokemon X/Y, and the fact that the one isn't wearing glasses. also, since we don't yet know Rei's brother's name but we might at some point, i "cleverly" avoided using it, whoops.

Rei adjusted his tie to maximum comfort, straightness, and properness. He combed his hair one last time, separating the few strands that looked better going the other way. He made sure his glasses were clean, and straightened them. He grabbed his backpack, and headed to the door.

"Have a good day at school, dear. Work hard," his mother called out.

"I will, thank you. Have a good day, mom," he called back, slipping his shoes on.

"Oh, and your brother is coming home this weekend!" his mom came out of the kitchen, still wiping her hands dry on a towel. She was beaming.

Rei started to smile right away, too. "Really? What's the occasion?"

"I don't know, he said he had some free time, so he'd come home. Maybe he just missed us," she winked at him. "He's coming in on a train tonight. I'll send you a text when I know what time so you can meet him at the station."

"Sounds good," Rei grinned. "Later, then."

Nagisa informed him that they were eating lunch on the lawn that afternoon, something about the sunshine and the lecture he got from the science teacher because he'd been goofing off with his lab partners in class. Rei didn't mind, but he'd initially assumed they were eating on the lawn because Makoto-senpai and Haruka-senpai were eating out there.

It was just him and Nagisa.

Nagisa stretched out in front of a tree, and started to complain about their science teacher. Rei liked the guy for basically the exact same reasons Nagisa hated him; he was tough on troublemakers and kept the class moving at a quick pace, and he had little patience for people trying to waste time in class. He would still answer serious questions in detail, though, and he was always clear on what material would be covered by the tests. He was a perfect teacher, as far as Rei was concerned. As a time-wasting troublemaker, though, Nagisa saw things differently.

Rei calmly ate his perfectly balanced lunch while Nagisa made extraordinary gestures and used a funny voice to mimic their poor teacher. It was shocking how amusing Rei was finding Nagisa. Normally, he had little to no patience for such mocking, and found students who didn't care about their education to be a hindrance, but... somehow...

Nagisa was just cute.

But, Rei didn't agree with Nagisa's points. He just listened quietly and ate.

Nagisa sat up abruptly. "Oh! That reminds me! My stupid sister finally brought home that show I was telling you about! How about we watch it this weekend?"

At first, Rei smiled, and he was about to say sure. In fact, his first thought was that maybe his brother would want to watch it with them. Then, he thought about that, and he had a mental image. All three of them, on a couch, watching a show...

Nagisa and his older brother...

"Oh, um... I don't think I can this weekend. F-family stuff," he shrugged, looking sheepish.

"Eh? Is everything ok? No one's sick or dead, right?" Nagisa pouted a bit.

He was so cute, even when he was being totally insensitive. "No, no, nothing like that..." Nagisa was still looking at him in that way, like he might burst into tears if Rei didn't tell him what was going on. In point of fact, Rei had never seen Nagisa burst into tears, but he knew how to make it seem like he would. Rei sighed. "My brother is coming home for a visit, so... might be... busy... at home." He filled his mouth with food and started to chew thoroughly.

"How exciting! You actually like your brother, right?" Nagisa asked, as if the idea of liking one's sibling was completely alien to him. "I'd like to meet him! I bet he had a ton of cute stories about when you were a toddler and stuff!" Nagisa laughed.

Rei's heart sank. "Ah... He's... he's going to be home for such a short time..." Rei hedged.

"Mmm," Nagisa frowned, and watched Rei. And then he leaned in, watching Rei from very, very close. Rei couldn't help but get nervous... "Are you hiding something from me?"

"Wh-why would you think that?" Rei stuttered.

"Hmmmm," Nagisa frowned.

The rest of lunch was quiet, but Rei couldn't calm down because of how Nagisa was watching him.

After practice, Nagisa insisted on following Rei home. That wasn't so unusual, since they didn't live that far apart. Rei's mother texted him about his brother's arrival, and Nagisa jumped on his back, so he saw. He tried to get Rei to go with him to the convenience store to get treats, and he tried to get Rei to let him come over so they could study. Rei wanted to do anything Nagisa wanted to, but he knew what Nagisa was doing. He was trying to stick with Rei until it was time for his brother to come home so he could go with and meet him. And that...

So Rei finally told Nagisa that he was tired and he wanted to take a nap before it was time to get his brother. Nagisa looked unhappy, but they parted ways at the intersection as they did when they weren't going together to one of their houses. Rei watched him go, feeling... like trash.

He tidied up the house for his brother's arrival, and when it was time to pick him up, he went out, already changed into normal clothes. He kept an eye out, though. He was pretty sure Nagisa knew when his brother was due, so.

All the way to the station, and while he waited, and greeting his brother, and going home... he didn't see Nagisa. So. That was fine. His brother seemed to be in good spirits, too, and he just teased Rei when Rei asked about his reasons for coming home, so.

That was completely normal.

His family had sushi for dinner, and his brother wanted to know all about this swimming thing and Rei told him everything he'd told his parents, and his brother was suitably impressed that he'd managed to learn the butterfly stroke well enough to qualify for regionals, at least in the relay, in such a short period of time. Feeling stuffed with pride, Rei took care of the dishes. On his way back to the family room to watch the ball game with his family, he checked his phone.

He had twenty texts from Nagisa.

Saturday afternoon, he went for a run with his brother, who insisted on breaking it into several short races. He only beat his brother once, which was somewhat frustrating, but afterward his brother bought him a flavored ice, so it was good enough. They went to the store to buy some treats, and his brother kept needling him about his girlfriend. Didn't he have one? If he didn't, why not? Of course, in Rei's brother's first year in high school, he'd had three girlfriends, and two of them were at the same time, and they knew about each other, and they didn't mind, because they both liked Rei's brother that much. Rei just kept tight-lipped.

On the way home, he checked his phone. Six messages from Nagisa, so Rei, feeling guilty, quickly replied. Rei's brother, just like Nagisa, threw an arm around him and checked his phone. He was convinced, then, that Rei had been holding out on him and that he did have a girlfriend, and her name was cute, Nagisa! Two hours later, after his brother had stolen his phone and read all his messages with Nagisa, Rei finally showed him a picture.

Of the swim team. And Nagisa. Who was not a girl.

Rei's brother laughed for ten minutes.

Throughout the evening, which was spent playing games as a family, Rei kept replying to Nagisa's texts. Rei's brother asked his mother about Nagisa and Rei's mother replied that he was a sweet, cheerful, very energetic young man, such a good influence on Rei! and Rei thought he might as well just be swallowed up by the ground. Rei's brother was watching him closely after that.

They took a bath together, with was annoying because they were too big and Rei's brother kept teasing him. Before he went to bed, he swapped about a dozen or more messages with Nagisa, which ended with Nagisa sending him kissy face and wishing him a good night.

Rei felt guilty enough to die, so he stared at the ceiling and went through his subjects, considering the formulas and principles that he had to keep in mind.

Rei thought his brother was going back Sunday, but apparently, he wasn't going until Monday morning. Rei tried to tease him about being a lazy college student, but it somehow got turned around to him being a spoiled high school student who didn't understand college life.

Shortly after lunch, Nagisa appeared at his doorstep.

Fortunately, Rei was the one who answered the door. All his previous guilt vanished, and the fear of Nagisa coming in and... he stepped outside, closing the door behind him.

Nagisa frowned. "Is it a bad time?"

"It's..." Rei looked over his shoulder. "What's going on, Nagisa?"

Nagisa made the saddest, cutest face. "Does something have to be going on for me to want to see you?"

"Well, that's not..." Rei started, adjusting his glasses. "It's just, like I said, my brother is here for a short visit, so it's..."

"My mom made loooooooots of strawberry shortcake last night!" Nagisa happily declared, as if Rei weren't even speaking. "And I don't know if your brother likes strawberry shortcake," and the look on his face suggested that if he didn't, Nagisa was going to assume he was from another planet, "but my mom makes it the best and the strawberries are super fresh so it's good to eat it right away so before my stupid sister gets any, I thought I'd share with you and your family!" he brightly declared, holding up a cute pink cake box.

Rei's heart sank. "Ah... well... we just finished lunch..."

"Perfect! Snack time, then! Or dessert! Whatever, it's strawberry shortcake!" Nagisa laughed.

"No, I meant..." Rei started.

The door behind him opened.

"Ah! I thought you were hiding your girlfriend, how disappointing! This is your teammate, right?" his brother asked.

Rei's heart sank to his feet. He looked from Nagisa to his brother.

His brother swatted the back of his head. "Rei, you idiot, don't just stand there gawking, introduce us!"

"It's ok, oniichan!" Nagisa happily beamed. "It's nice to meet you! I'm Hazuki Nagisa, and I have cake!"

"Well, cake is always good. In moderation," Rei's brother laughed.

"Ah! As expected of Rei's big brother!" Nagisa happily laughed, going around Rei to accept Rei's brother's tacit invitation inside.

Rei felt defeated.

He followed Nagisa inside, in time to see his brother pat Nagisa on the shoulder before going to get small plates. Rei tasted bile in the back of his throat. He quickly moved to catch up with Nagisa, in time to push him aside so he couldn't possibly be sitting near Rei's brother. Nagisa made a face at him, but he just took the cake out of the box. Rei's brother came back with the plates, and messed up Rei's perfectly arranged hair.

"Why don't you get us some drinks? What do you like, Nagisa-chan? Milk, milk tea...strawberry milk?"

Rei frowned, thinking his brother was mocking Nagisa, and hating the way he was already speaking to Nagisa so casually. However, Nagisa just bounced cheerfully. "You have strawberry milk!?"

"Rei wouldn't mind going out to get his best friend some, would he?" Rei's brother grinned, tousling Rei's hair again. Annoyed, Rei quickly straightened his hair out.

But. Wait... his brother... was just trying to get him out of the house, wasn't he? "I'm... not... no! Nagisa-kun isn't that particular, right?" Rei looked at Nagisa.

Nagisa... was looking at Rei's brother, and he was... grinning? "Ah...! But strawberry shortcake... with strawberry milk... wouldn't that be the best?"

"Then... you go, oniichan," Rei glared at his brother. "That's what good big brother's do, right, they spoil their little brothers?"

"But I'm pretty much a visitor!" Rei's brother pouted, which did not look cute on his face at all. Plus, he sat down right opposite Nagisa. "And Nagisa-chan and I want to get to know each other better, right?"

Nagisa giggled. "Sure, sure, Rei's big brother! It'll be fun to get closer!"

Rei felt something dark consume him. "Well, if I'm in the way, then fine, I'll go!" He stood up, perhaps a bit dramatically, pushing his chair all the way back until it wobbled and nearly fell over. He headed straight to the door, ignoring Nagisa's calls, and slammed the door on his way out.

He forgot his wallet.

He forgot his keys.

He was wearing his dad's shoes.

Dejected, he slunk off to the nearest stairwell, and sat down on the steps, putting his head in his hands. He'd been a jerk. And he'd made a fool of himself! In front of Nagisa!


He could have guessed that Nagisa would follow him out. It was just Nagisa's nature; he didn't let go. But, Rei just sat there, holding his head, and waited while Nagisa sat down.

"I'm glad you didn't get further away! I wasn't sure I'd be able to find you if you took off at top speed!" Nagisa bumped into him. "I've got your wallet and keys, you know. So we can get back in. ...I think your brother's worried about you. He's so nice!"

"I didn't want you to meet him," Rei said mournfully. Then, he heard what he said. "I didn't mean it like that..." he peeked at Nagisa. "I didn't mean... I wanted him to meet you... I didn't want you meet him..."

"Mm... you wanted him to stalk me?" Nagisa winked at him.

Rei couldn't help smile a bit. "My brother... as you can tell, my brother and I are a lot alike. I mean, we look alike. Except... he doesn't wear glasses. And we're both athletic. But, he's a bit... a bit bigger, broader shoulders... he was the captain of his track team, he competed in multiple events. He was always... really popular, too. He's smart. Oh, but he was never top of his class, but..." Rei shrugged.

"See! Rei wins!" Nagisa threw his arms up in the air.

He was cute. Smiling softly, Rei continued, "I really love and admire him. I've... always enjoyed being as much like him as I am, always wanted to be even more like him. I've always thought of myself as... his little brother, his... second best, I suppose. And that's never been a problem for me! Because I've always thought of him as the best, too. But, when I thought of you thinking of him as being the best..." Rei sighed.

It sounded stupid when he said it out loud.

"Aww, Rei-chan..." Nagisa smiled. He bumped Rei a few times. "Do you think I'm really shallow?" he asked. He sounded upbeat, but...

Rei reared back. "No! No, of course not! Not at all!"

Nagisa snickered fiercely. "But, you still think I'd stop liking you if I found a better version? Do you think I'd trade up? Start making out with oniichan while you were out buying strawberry milk?"

Blushing madly, Rei dipped his head down in shame.

Nagisa slipped his arm inside Rei's arm.

"It's... it's not like that... I know it's not rational, and I shouldn't have behaved the way I did. I know I'm not even number one in your mind. That's probably Haruka-senpai. It's just. You... are important to me, and... Even though I know we're... we're not like..."

"Do not finish that sentence if you don't want me to shave you again, this time, a lot closer," Nagisa said firmly. He had a serious look on his face. Rei was a little afraid. "Rei-chan, you're the smartest person I've ever known, and you're still an idiot. It's hilarious. I don't like you because of your looks, even though I do like how beautiful you can be. I don't like you because of your accomplishments. I like you because you get up in the middle of the night to swim in the ocean... even though that was really stupid..."

Rei blushed harder, which made Nagisa snicker more. He snuggled Rei's arm, and continued.

"I like you because you're totally serious, but you still know how to have fun. You go along with my goofy plans! I like you because you're strong enough to go face off with Rin-Rin when he was being an asshole. And you're noble enough... to sit and watch the rest of us swim without you..." Nagisa's voice got quiet and he clung hard to Rei's arm.

Rei felt warmth spreading all over his body.

"How could anyone else be my number one? It's just not logical!" Nagisa beamed, leaning forward to look into Rei's eyes.

Nagisa's face was so bright and cheerful and cute and adorable...

"I love you," Rei admitted, face burning. "I'm sorry. I should have trusted you..."

Nagisa laughed, and leaned in to kiss Rei. Rei bucked back, looking around quickly to see if anyone saw. "Aw, Rei-chan! Don't be so shy! You'll hurt my feelings!" Nagisa pouted, but it was the same pout he used when the teacher gave him a really hard question in math.

It was a persuasive pout.

Rei relaxed a tiny bit, but he was still checking to make sure no one could see them. "I'd like you to get to know my brother... he's really great, and..." Rei's parents already liked Nagisa. Rei really wanted Nagisa to feel comfortable in his home.

In his family.

Nagisa swept in and kissed him again, and this time, Rei allowed it. At least until Nagisa tried to slip his tongue in... "Hey, hey... there's cake, right?"

Nagisa pouted, this time a real pout, but then he laughed. "That's true, and oniichan will be worried about us. Ok, let's go!" Nagisa jumped to his feet and held his hand out to Rei.

With a bright smile, Rei took Nagisa's hand. All right, they were going to get strawberry milk... and go back and have cake with his brother!

Monday morning, Rei went with his brother to the station before school. Of course, that meant he carried his brother's bag. Well, that was fine.

His brother's train left just ten minutes before his, so they didn't have much time, and his brother kept messing with his hair, but Rei took it in stride. He could fix it after his brother left and before he met Nagisa on the train. Just as his brother was picking up his bag to go, he grabbed Rei into a rough guy-hug. "Hey, little guy. Your girlfriend is pretty cool. Don't mess it up!" He winked at Rei, really ruffled his hair, and got on the train.

Rei was too flustered to speak, and even twenty minutes later when Nagisa was tugging on his arm, he couldn't explain why he was smiling so creepily.