I think Sebastian encountered this man when he was on his own investigating people during one of Our Ciel's missions or Sebastian sneaks out at night sometimes to have fun since demons don't need to sleep. Maybe this guy is a one night stand of Sebastian's that died like beast did? Maybe that's why the man called Sebastian a "demon". He probably meant it literally and figuratively? There's going to be a lover's quarrel in the next chapter lol
I think Sebastian encountered this man when he was on his own investigating people during one of Our Ciel's missions or Sebastian sneaks out at night sometimes to have fun since demons don't need to sleep. Maybe this guy is a one night stand of Sebastian's that died like beast did? Maybe that's why the man called Sebastian a "demon". He probably meant it literally and figuratively? There's going to be a lover's quarrel in the next chapter lol