A/N: Okay, so if I say so myself, there has been way too much Makoto/Haruka/Rin action in my fanfics lately. I need to branch off to other characters. Thus, I am writing Rei and Nagisa again. It's been a long while since I've written them, so hopefully I can get Rei down this time.

This is based on an art post going around tumblr (don't have the link on me, sorry) where it shows Rei and Nagisa as first years, and then as third years.

Pairing: ReiGisa

Warning: Implied sexual content, fluff

Disclaimer: I don't own Free!/Swimming anime

"Rei-chan~!" Nagisa shouted through the empty locker room.

Lifting his attention up from his book for a moment, Rei pushed his glasses up on his face and watched as Nagisa came towards him with a bright smile. The corner of his mouth twitched a bit, about to give way to a smile, but the honor student quickly steeled his expression before that could happen. He shut his book softly and pushed it into his backpack. There was no point in attempting to read while Nagisa was trying to get his attention. The younger male was just too energetic and hyper to focus on something else. He practically demanded attention.

"Yes, Nagisa?" he asked.

Grinning from ear to ear, Nagisa leaned over a bit so that they were looking right into each other's eyes. A bit caught off guard by the sudden proximity, Rei found himself blushing just a little bit. He pushed his glasses up on his face once again, much more out of habit than necessity. "You don't have to be so close, Nagisa-"

"Why, are you embarrassed, Rei-chan~?" Nagisa's voice dropped a few octaves and a familiar playful smirk came to his face.

Shivering a bit at the purred statement, Rei licked his lips before averting his gaze. Nagisa always seemed to do this whenever they were alone with each other. He easily switched from innocent boy to seductive man in no time at all. It was really disorienting for Rei, to say the least. He was a person who gained as much information about a subject as possible. So naturally, before officially joining the swim team, he had done some research on the members. And honestly, nothing about what he had found had surprised him.

Makoto was the nice, sweet type who catered to others and treated others equally without any explanation. He rarely became upset or lost composure. He was also always seen with Haruka, whom he had been friends with since they were children. His selflessness and caring nature, in turn, was the reason for becoming the swim club captain.

Next was Haruka. He was the best swimmer in the club, without a doubt. He had a strange interest in water and fish, more specifically mackerel. He had a cold demeanor and didn't allow anyone other than Nagisa and Makoto close to him. However, when he was around friends, he relaxed much more.

Nagisa was the youngest and most innocent in the group. He had a child-like attitude about things and always seemed to look for anything fun and exciting. He was over-the-top and rushed into situations headfirst without thinking. However, there was something about him that made people like him rather than hate him.

Except that that was just the surface when it came to the blonde. It wasn't until he was alone with Nagisa that he started to understand that everything he had learned about the other male was in fact, utterly wrong.

Nagisa wasn't innocent at all. It was just a front that he played in order to take people off guard. Sure, he was a very nice kid that had good intentions. However, that didn't mean that he didn't know exactly how to act to get what he wanted. Case in point, just a few days ago at a local cafe that they went to. Nagisa had seen a shortcake that he really wanted to try, but he didn't have the money to pay for it (he had already tried to convince Haruka and Makoto to pay for it, who both refused because Nagisa and sugar wasn't a great combination). So, he turned his childish impressions onto the young female cashier who didn't know what hit her.

Needless to say, Nagisa is a manipulative little brat who knew exactly what he was doing to Rei at the moment.

Coughing into his fist, Rei pushed up his glasses to try and make himself look as though he was composed. However, based on the amused gleam in Nagisa's eyes, that wasn't working out too well. So, he took to standing up suddenly and heading towards the door. Being alone with Nagisa wasn't a good idea at all. It made him feel flustered and weak at the knees. He needed to go out to the pool where Makoto and Haruka were.

However, before he could leave the locker room, arms wrapped around his torso, stopping him in his tracks. The blush on his cheeks grew brighter and he tried twisting around to look down at Nagisa. However, the younger male had such a tight hold on him that it was near impossible to move. So, he could do nothing but stand there and let Nagisa hold onto him.

"Nagisa...," Rei trailed off, coughing awkwardly.

"Yes, Rei-chan~" Nagisa hummed happily, nuzzling his cheek against his bare back.

Shivering a bit at the touch, Rei just blinked for a moment before sighing. "...Nothing. Nothing at all."

Three Years Later

"Rei-chan~" Nagisa called out to him from the locker room.

Rei shoved the rest of his clothing into his bag before he straightened up and gazed over his shoulder. Seeing a familiar mop of blonde hair coming towards him, Rei sighed and pushed up his glasses. It was too earlier in the morning to go through this-

A loud grunt left Rei's mouth as Nagisa practically collided with him. He cursed mentally as his glasses slid off of his face, falling down towards the ground. He was about to lean over and grab them, but he found Nagisa's arms wrapped around his waist, pulling him close to the other boy's chest. Breath hitching in surprise, he gazed over his shoulder and locked eyes with mischievous honey eyes.

"He's so tall now...taller than me," Rei thought to himself.

It seemed to have happened overnight or something. One moment, Nagisa had been much smaller than him, barely coming up to his collarbone. But now, he was a good few inches taller than him. And not just that. Along with his sudden growth spurt, his face and body filled out as well, losing some of its baby fat. He became leaner, much more lanky. It was like jumping into a vat of cold water.

When he had posed the situation to Nagisa, the younger male chuckled before pulling him into a kiss. It seemed as though the blonde had taken great joy in being taller than Rei. Being along with Nagisa was much more dangerous now than it had been before his growth spurt. Now, the other male could actually pin him down and keep him down. With his growth spurt seemed to have come a sudden burst of strength.

It just made Rei's life harder, truth be told.

When he felt sneaky hands suddenly slip under the band of his swimsuit, Rei jumped in shock and his hands shot down to stop Nagisa. "W-We can't do that here! We're in a locker room!" he hissed out, glaring at Nagisa over his shoulder.

A smirk came to Nagisa's face and he leaned his face forward, pressing his lips against Rei's temple. "Then I guess that we had better hurry before someone catches us, hmm?" he murmured against Rei's skin before leaning his head down and licking a strip up the other male's neck.

Sucking in a harsh breath, Rei shook his head and trembled in Nagisa's grip. "N-No...I think t-that we should j-just...s-sto-...a-ahhh..."

A/N: I like the fact that Nagisa gets taller and turns into even more of a mischievous/sneaky boy when he's in his third year of school. u