I have used machine translation to look at the strings from Russian, should I post spoilers…? It doesn’t spell out how to start the affinity, but the first string is tantalising:
“After your fifth pint, you start talking to the tavern waitress.”
Viewing post in Secret ending
seems fairly conclusive, though I have no idea how to drink at the tavern. I feel like i've tried clicking everywhere in there, no extra options to be straight when drinking the orientation swapping beer, and no way to enter not at night. Are there any beers we can take with us to the tavern? Does the shield above the fireplace mean anything?