3 parts Complete MatureSmut with a plot. I'm horny, don't judge, you're here too ;)
TL;DR: Xiao has been answering Lumine's calls, which have been suspiciously date-like. A bond forms. Altered dreams. Slight bondage kink. Edging.
After the Chasm, Lumine felt herself falling for this strange, aloof Adeptus. So calm and composed, caring for the people of Liyue, ever vigilant and thankless. She honestly just wanted to help him, ease his pain if she could, same as she would do for anyone who was hurting. She hadn't anticipated actually falling for him. He was unreachable, detached, foreign. But god, did she want him. Tormented by dreams of him kissing her, caressing her. Loving her.
Xiao loves Lumine. He has tried to deny it, but he can't. He has accepted this. Accepted his place beside her as her protector and nothing more. He may love her, yes, but the only way he can show it is by being at her side. He cannot allow anything more. He is cursed, filled with evil karma and hate. Should he touch something so delicate, so divine... he would corrupt her, destroy everything that is beautiful within her. He CANNOT let that happen, no matter what torments he endures. She is all that matters.