Tea dealer

Hm I’m sorry to ask this but I can’t remember the name of a fucked up manga I read a long time ago
It starts with a boy summoning a demon (turns out he’s super high rank) and asks him if he can eat him... later in the demon world he works in some brothel (??). A demon can’t say the name of a higher one
Sorry again to ask for this ( T﹏T )

Once I saw a mangago user with a ppf of the same color of the website's background and with a username made of spaces.
It haunts me.