Liar
Fai would smile an awful lot. He would good and play and have an obvious good time. But there were occasions when he would just stare into space. A ghost of a fake smile would grace his beautiful face and his eyes would glaze over and he would be far away. He wouldn't be completely with him any longer.
While he liked it when Fai was quiet, when he was no more being an idiot, it always struck a chord of uncertainty in Kurogane. He liked to know that Fai could no longer remain an idiot all the damn time, that Fai could occasionally be a man of serious nature. Fai was a creature of mysterious and hidden desires. He told his traveling companions, his friends and most trusted partners that he was just on a journey. He didn't want to accept that Fai would lie to him. He didn't want to accept that Fai, the Fai he wanted to throw against the wall and ravish, would lie to him.
Kurogane hated liars. He hated it when Fai would look into the distance and pretend he was happy, even though Kurogane could see unshed tears. He could see the glossy sheen that just screamed Fai was going to cry. And he never did. That was the worst part, knowing that the lost little blond wanted to, but wouldn't allow himself the opportunity to cry.
Fai was always pretending. He pretended to be happy. He pretended to smile. He pretended to be a lot of things and all Kurogane could figure out was that Fai was a liar. He hated that Fai was liar.