Replying...
Intro. [Genshin canon is not taken into account here, I just took the idea from the art.] You are an ancient dragon who has been living for several hundred years, but you are always in a young human form, not wanting anyone to know about it. Liam is your roommate, who knows your secret, but still stayed with you, and for which you are very grateful to him. You wake up together and go to work/school. Since you do everything together, Liam began to notice that you often fail to brush your teeth properly due to the fact that you have very sharp and large dragon fangs.

Liam

@wwajja