Disclaimer: I do not own anything. I haven't read any Free! Iwatobi Swim Club fanfictions (sadly) so if this plotline is similar to any works out there, believe me, it is nothing but co-incidence. I swear. To be honest, I just finished watching the series today because damn college and stuffs.

Summary: AU. Upon his sister's persuasion, sex-addict Rin Matsuoka consults therapist Haruka Nanase. Heartbreaks. Turmoils. Sex. Older!Haru. RinHaru.

SWEET SERENITY

Prologue

It wasn't falling in love, it was nothing but falling apart.

"Fuck…Oh my god, Rin! Yes!"

Rin Matsuoka smirked to himself as he slid another finger, feeling her inner muscles clenched against his fingertips and her head thrown back in euphoria. He almost sighed in boredom as the nameless woman screamed his name and orgasm, whimpering to his touch as he pumped his fingers into her faster and faster.

It was the same routine.

He would look for a beautiful girl – as if he would pick up some ugly slut, not with his body that deserved only the best. Then he would stop her, whispering something in her ear that would certainly make her giggle then she would follow him into some empty classroom, and it would soon lead to…

"Rin! God! I'm…I'm coming!" The girl screamed for almost the umpteenth time.

…this.

He felt more amused than aroused. He pressed his lips against her nape, hearing her gasp out his name. "That has to be the third time you said that." He whispered and she moaned in response as he slid a third finger into her.

"Oh, God Rin…" she whispered, wrapping her arms around his neck, biting her lip, shutting her eyes tightly.

"There's nothing to be embarrassed about that." Rin assured her while pumping into her faster now. Then her childlike eyes burst open and she screamed his name at the top of her exhausted lungs. "In fact, girls usually have orgasms for six times straight when they're around me." He stated, sounding factual, like a teacher in a classroom.

And that's true because Rin Matsuoka was a great lay. What girl could resist him? He was the epitome of perfection. His brownish-red locks swept over his gorgeously red eyes. His body built could contest that of a damn Greek god, with his muscles shaped and toned in the most perfect way. His hygiene was immaculate. He almost believed that every pore on his skin could release an intoxicating fragrance that no woman could get enough of. Then his dick. Oh god his dick was a work of masterpiece. It was perfectly shaped, nice, thick, and the perfect shade of pink. Girls loved pink.

His train of thoughts was interrupted when the door of the classroom opened and a familiar voice broke into his protective barrier, trespassing his wall of defenses.

"Nii-san!"

There stood his little sister, Kou Matsuoka, her eyes widened and her mouth opened a little before she dashed out, slamming the door behind her. Rin quickly pulled his fingers out of the girl, ignoring her call for him to return.

There was Kou outside the door, her back facing the cursed classroom.

As Rin shamefully wiped his fingers on the fabric of his school uniform, he walked towards Kou in one swift motion. He found that his fingers were still sticky and he snarled disgustingly as he cleaned it more profusely. He placed his hands on his pockets before hanging his head shamefully like a pathetic dog.

"Kou."

Soft patter of light footsteps on cold tiled-floor resonated throughout the empty hallways and Rin cleared his throat as his little sister turned around to face him.

"Nii-san, you need help." Her voice was cracking and Rin could tell that she was hurt and on the verge of crying. Still, he couldn't help rolling his eyes upward and keeping them there as he spoke to the fluorescent lights above him.

"…You think so?"

From his peripheral vision, he saw Kou reach something in her pocket before handing it over to him. Her eyes were downcast and she didn't even look at him. How could she? Rin would never admit this out loud but sometimes he couldn't even look at himself. He looked over at what his sister was giving him and saw that it was a small white business card.

"What's that?"

"I already set up an appointment for you with a therapist named Haruka Nanase. Please seek his help, Nii-san."

TBC.