Newbie at writing FRobin, but this was for a prompt in Tumblr, so here it is. :)
"Just existing is never a sin!"
Robin knew right at that moment that something was odd. Really odd.
At the time, she was clouded by darkness and enveloped by despair — a sin she has been called since she was a kid, so a sin Robin believed she was. At the time, she had no hope of any kind and had decided that, if she was truly a sin, then death didn't seem so bad.
But then, this strange man — he was really weird, what the hell was he? Half-robot, half-human? Odd — spoke the words that really hit her hard. Words that knocked the air out of her lungs and left her completely wide-eyed. How did he know what she wanted to hear for so long?
Did he read minds? Did he know something about her? Did they meet somewhere before?
In this life? In another life? In another reality?
But Robin didn't believe in such a thing — she was a woman of science after all. The archeologist believed in facts, tangible things, things that were written by people who actually lived in the same world she did. But that odd cyborg messed with her beliefs and she couldn't stop thinking that, maybe, they were meant to find each other. It can't be just a coincidence.
But calling it destiny was a bit of a stretch and soulmates are a huge question mark that no human being had ever been able to answer. However, looking at his sleepy face every night while she reads a book, Robin couldn't stop wondering that maybe it isn't that much of a stretch and that she might have figured how to respond to that question.
Perhaps common reason needed to be tested sometimes.
She stroke his hair with her Hana Hana no Mi and Franky slowly opened his eyes. "Hey, Mr. Cyborg."
"Hey, Nico Robin", he shot her a crooked and lazy smile.
"Just wanted to let you know I'm happy I've met you", Robin grinned. She wasn't a corny person — that was Franky's role after all, but she was sincere. She lied for far too long in her life and she finally got tired.
"Yeah, me too."
"Do you think we were supposed to meet each other, Franky?", she asked in a curious tone.
"Nah, probably not", He just raised an eyebrow, "Do you believe in that kind of stuff?"
Robin stared at him and he held her gaze. It got to have an explanation for two human beings being able to be so in sync, on the same wavelength, and to understand each other so perfectly. The archeologist always liked logic, she was guided by that, but maybe some things didn't make sense.
And while she looked at him and all his features, from the carefully brushed hair (he always said he doesn't care about that, but she can see through his lies every time) to his delicate eyelashes to all the machinery that existed inside him. He was a cyborg (much more of a robot than a regular man now), but the heart remained the same.
So she ignored logic.
"I didn't, but somehow I started believing when I met you, fufufu", she chuckled.
"Awww baby, you love me that much? I always knew I was SUPEER!", he made his signature move somewhat in a sluggish movement and she just rolled her eyes.
"Franky, we've been together for quite a while now. Of course I love you, don't be silly", she poked his nose. Franky smiled and pulled her to lay down with him. She knew what he wanted — the cyborg liked to be the little-spoon, he liked to feel her on his back.
Robin settled down behind him, resting her head close to his neck and begun to stroke his chest in circular patterns. Franky was silent and she knew he had something on his mind. Maybe she had said too much? Robin frowned and was about to ask him about it when he suddenly spoke again.
"So. Soulmate then? Is that what you're saying?", he asked a little skeptic. She could understand the lack of belief in the subject, but Robin really thought it was the only explanation for their connection.
"Mmm-hm. Is that impossible?"
"I don't know. That'd mean we believe in fate. Do we believe in that?", he asked softly.
Robin nuzzled in his neck and said with fondness in her voice, "To be honest, I believe in us. So if the name for what we are and what happened to us is 'soulmate', then so be it."
"Mhmm, soulmates, huh? Too bizarre, but listen, if this stuff would make me find you in another life or some shit like that, I accept", he chuckled.
Robin laughed and he gave a soft kiss on her hand. She liked the idea of searching for him anywhere — if there's this thing of another life and even if she might not be Nico Robin there, she'd still like to meet him and be with him. There was no explanation for that, but she didn't care. Franky would always be the man she'd choose.
"Okay, okay, Mr. Cyborg, I'll see what I can do."