Engetsu
To understand the demon's nature, you had to remember his origin. While he did form an individuality, and his nature was indeed demonic, his soul was more like a cluster of human grudges and desires, fallen victims of the battlefield merged together. Because of that, you could say the blade was almost human, and could feel the same compulsions as humans, such as hunger, thirst and more.
More, like what he had just been subjected by. And because of how off guard he had been taken, even if he could put two and two together, his mind didn't even think about it.
He covered his mouth and just looked at the godslayer eating her cake peacefully, unperturbed by his teasing. But this was strange, truly strange. He felt strange. Different. There was a smell that he couldn't ignore, and the more he noticed it the more he realized he liked it. Then, he realized just where this smell came from, and his usually composed lips curled like a snake as he looked away in embarrassment.
How could he think such indecent thoughts? She was a cute girl, it was pointless to deny that. Maybe she was even his type, if he had one in the first place. Even so, all of these thoughts just came and invaded his head at once. No, they didn't invade him, he couldn't even say that they came from somewhere else. The fact that Lizzie just became this much more gorgeous was a fact, and even when looking away he couldn't help but keep seeing her.
The way she looked at him, her quiet breaths as she ate or spoke to him, and even the tea couldn't rub off the taste of her lips from earlier anymore, even as he tried to compose himself by drinking it.
This was unlike him, he felt so strange. If he ordered alcohol, he might understand, though even then a spiritual entity would hardly get drunk. Was this tea spiked somehow? He couldn't understand, all these feelings and urges suddenly filling his head, and these thoughts that he couldn't bring himself to ignore. She might as well be wearing a hundred coats, it wouldn't make her naked form any less vivid in his head, and the things he thought doing to it. How her skin sometimes seemed to glisten, or how her golden hair was truly pretty. How he wanted to feel all of those things...
It was inappropriate, shameful of a sword to even think such things, and he hated himself for it. But he didn't know why, he couldn't help it.
She was getting closer to him. He wanted, no, needed to hold her closer to him. His legs shifted awkwardly while he thought of how her hands pulled him to her, so powerfully, how she would touch him. He wanted to do fun things, and didn't know how to deal with it.
Without even realizing, he wasn't even looking away anymore, and the face in his head and the one in front of him happened to become one and the same. He had certainly turned away, but had been getting closer and closer, and now the two were so close they were almost touching. His entire body a glowing pink while his hair flickered like a crimson flame once more. He couldn't even tell what was happening anymore, all he wanted was to stop this itching sensation, even if it meant comforting himself to do so. It was too pathetic for words.