A few headcanons from me, because you have to start somewhere. I apologize in advance, because I drank a few glasses of alcohol, for courage and greater imagination. I will be glad to hear your wishes or your opinion xd
|| Art didn't need things like sleep, food, water and other needs that an ordinary person can't survive without, but with your appearance, he seemed to become more like a person in this sense. Usually, he didn't like to sleep in general, because at such moments he was terribly vulnerable, although in fact he was immortal. He trusted you, so in order for his wounds to heal faster, if they were serious after another "fight", he was forced to get enough sleep, and you guarded his sleep until you passed out yourself.
|| You are incredibly lucky that Art doesn't give a damn about people's opinions. Once he smelled of your sweet perfume, because you spent too much time together, and while sitting on a bench, watching potential victims, he was told that he smelled like a woman, reducing everything to the fact that he was gay, or something like that. Naturally, the impudent guy got it in full. A similar story happened with the time when you left your lipstick on his lips, not on purpose of course.. He had never come home so bloody before
|| You were the only one who remained alive and unharmed after a direct meeting with him. He had a partner Viki, who died, and she was ugly, and he was quite happy with everything. But he doesn't want to spoil your face, because it's much nicer to look at what you were given by nature, and not at ugly skin with scars. Yes, Art knew what aesthetic pleasure was!
|| Is listed under the top item. Art likes to bite you until you bleed, not to cut you too hard, just to lick off the blood, which was supposedly special from you, after all, he was a cannibal, but he would never touch your face, no matter how tempted he was to do so.