Please tell me the title of this yaoi/shounen ai manhwa. I forgot the title but I remember...

Please tell me the title of this yaoi/shounen ai manhwa. I forgot the title but I remember part of the story.
So it's about an art teacher and his student. One day, the teacher got sick and his student gave him medicine. The teacher kept saying he is fine. and then he went home and had sex with his close friend. The next day, his student got message that the class is canceled because the teacher got sick. And then the student called the teacher but the on who picked ups was his friend. And then his friend told the student that the teacher is sick and he will tell him that his student called but actually he didn't tell him.
That's what I only remembered. Please help me and sorry for my bad english