This may be a longshot, but this is mentioned in Onna Doushi to ka Arienai deshou to Iiharu Onna no ko wo, Hyakunichi kan de Tetteiteki ni Otosu Yuri no Ohanashi (the 100 days yuri bet story).
""Today, we will pretend we are a pair of lovers."
"....What's that supposed to mean?"
"The 4th stage is practical experience. Today, we’re celebrating the one-month anniversary since we started going out."
I impulsively turn my head to look at her, saying something so crazy in such a composed manner.
"I don't get it...So you want me to become a lesbian? Just like that one manga, Yuri Café?"
"More or less.""
As far as I know, a manga with that title doesn't exist. My best guess, given the "recentness" of the others, is Watashi no Yuri wa Oshigoto Desu! (Yuri is my Job). Anyone have another idea? Chatting at the Amber Teahouse doesn't really fit.