Disclaimer: I do not own Final Fantasy, and am making no money off of this.
Still
They never could understand how he did it. I mean, sure, all of them (even Vincent himself) enjoyed to watch Yuffie's antics... for a while. But somehow, long after even Tifa's infinite patience with the ninja had run out, Vincent would still have that ghost of a smile on his face. Cloud even asked him once, how he put up with her. Vincent had just smiled and said nothing. It wasn't that he couldn't explain it; he just didn't want to. It was their, or rather his, secret. That on those nights when Yuffie would be sitting in his lap, curled up against his chest listening to his heartbeat... when he wrapped his claw around her while stroking her hair with his human hand... when the Great Yuffie Kisagari was smiling and serene and so still... Though he didn't tell anyone, those were the only times he didn't feel like a monster.