Sakura always imagined her first time with Sasuke. There was simply no other way to do it. She'd rather die a virgin than to be touched by someone else.
She took care of her skin and body as a religious ritual. Sakura was preparing herself for the day Sasuke would see her, really see her, and award her salvation.
That day didn't come for a long time.
When the war was over, Sasuke didn't return. Not completely. There was no more animosity since he had been a key-factor in the alliance's victory, but he felt as if he didn't belong anywhere. Sakura could relate. In reality, the only place she thought she would ever really be a part of was Sasuke's side.
So she waited for him. As she had done most of her life.
At least, she didn't needed to be jealous. Sasuke wasn't exactly a lover. In fact, Sakura always expected their future relationship – if there should ever be one – a sort of romantic asexual.
She hoped, however, that he would give her the chance to feel him inside of her once. Just once. And she wouldn't ask for anything else.
One day, he returned. It was the day Naruto would be named hokage, at last. Sakura's heart sunk when she saw him at the ceremony, his rare smile directed at Naruto.
For the first time in nearly forty years, she gave up hope. Sasuke was back – and he didn't even bother seeing her. Talking to her. Warning her of his existence.
She returned to her house that night as a bitter old woman. She felt lonely and pathetic. Ino, Tenten, Hinata, Shizune – all with their respective families, all real women. And she, a shadow of a teenage girl.
When the sound of an intruder woke her in the middle of the night, she thought she was dreaming. In front of her bed, there was Sasuke. Older, rougher – but still as beautiful as ever. And from his lips, the words she had waited thirty years to hear :
"I'm sorry"
She took his face in her hands. Hesitating for a moment, she finally kissed him, with the kind of courage she never had before.
The kiss lasted for a long time. She guided him towards her bed and finally lost her virginity the way she had always to, though she did had to wait until she was middle-aged to do it.
She didn't ask how or why. And Sasuke didn't elaborate either. It was if their entire lives revolved around Sasuke's inquiry of his nature, the village, life itself, and the final result of that lifelong reflection had been his return to her arms.
They left the village soon after that. Sakura had already trained a capable pupil by then, one who could replace her (though she was deemed irreplaceable by most, just like Tsunade before her). Naruto was happy and sad. But the three of them were never meant to be, and Sasuke always had the ultimate choice.