We Three Are One
The first time Sasuke took Sakura it had started out perfectly, like a fairy-tale romance. They met on the battlefield after killing Orochimaru and he was shaking and she was blood-soaked and he grabbed her and kissed her like his life depended on it.
But in the bedroom she forgot that she had the potential to be the strongest kunochi in Konoha's history and he forgot he didn't know everything and she became the meek little girl she had always become around him, and sucked her stomach in and tried to remain in a sexy pose and struggled not the cry when he fell miles short of her expectation, whilst he cursed himself for not knowing how to reach out without force.
When Sakura first took Naruto it was indeed her taking him, because she was sick and tired of it all and he loved her, and they were high off winning a battle and slightly drunk because Jiraya and Tsunade thought it was funny and Naruto lay under Sakura as she took from him what she wanted, and found herself screaming in a way Sasuke could only hope to make her. And Naruto surprised her and tackled her and made her realize that life wasn't so dramatic after all. But he didn't make her heart leap like Sasuke, and there wasn't that sense of development. They were still incomplete.
The next day she couldn't stop him from slipping his arm around her waist and lording it over Sasuke. And although Sasuke had said he didn't mind if Sakura went out with Naruto, because they were team seven and all one, and it wasn't like he cared anyway, really, it occurred to him that perhaps he did mind very much that Sakura and Naruto were having fun without him. There had been three years of that, and he did not want to be left out any more. And maybe he cared, a little.
So when Sasuke and Naruto took each other it was not wonderful. It was biting and scratching and hatred and rivalry all rolled up into overwhelming lust, and they nearly bled each other dry before Sakura wriggled in-between them and did what she always did: acted as a mediator. And with Sakura there they remembered that they were team seven and suddenly they were laughing again and bantering and loving all at the same time.
Kakashi didn't take them all, which he could have done. He saw the long scratches on Sakura's arm where Sasuke had been taunting Naruto about his inability to make Sakura make that face, and Naruto had forgotten he was holding onto her and had dug in too deep. So Kakashi gathered them all up and told them off for not being a team. He radiated anger towards Sasuke and Naruto and warned them not to use Sakura to get at each other, and ordered Sakura not to let them. Then he gave them the second novel of Icha Icha Paradise and told them all to read at least chapter four, as that would give them a few ideas.
And then he took Sakura aside, put his hand on her shoulder and told her that whilst this was perfectly natural, and in fact was what often ended up happening in three 'man' teams, that she wasn't to allow herself to be drawn in and spat out, for this would destroy her. He murmured that he had known a woman it had happened to, and that if Sakura wanted one boy but not the other, and was dealing with both of them just because, it was best to stop it now, before it went too deep.
When he dropped his arm from her shoulder and caught her two eyes with his one she blinked and he seemed a bit closer and for a moment she thought he was going to kiss her forehead or something weird like that. And then it occurred to her that he might go a few inches lower and wondered what it would feel like; to be touching cloth but feel warm wet lips underneath. She was just starting to speculate if she should suggest to Naruto and Sasuke that Kakashi was a member of team seven too when Kakashi moved and she turned up her face expectantly. But Kakashi was Kakashi, a broken man, and so he awkwardly patted her on the shoulder again and disappeared. He did not come back.
So Sakura went back to Naruto and Sasuke and pushed Sasuke to the ground and climbed on top of him and demanded he not say a word. Half an hour later they both shuddered to teeth-breaking climaxes and realized that they preferred things this way, and that now Sakura didn't have to forget she was strong and Sasuke didn't have to pretend he knew what to do.
And then Naruto slid up hopefully behind them and whispered in their ears that perhaps they should go buy some ramen, because he was starving, and he knew he was going to need his strength to try out a new move he had learnt from Icha Icha Paradise. And with laughter and pseudo-sharp words they all got dressed and tumbled together down to the ramen shop, arms and hands and mouths and tongues all free to roam between the three of them, because they were one. Flawed, confused, loving, hateful, loyal, strong and weak, they were one.
And so the story started.