I've decided to go with the "Fuck NT rules" path. If one offers me something, and I want it, I'm not going to try to decode if they are "being polite". Don't offer me shit you don't want to share.
If I feel like buying someone coffee or food, either it's on MY whim, or if it's repayment, it's cause it was discussed beforehand.
I'm just done with appeasing allistic bullshit just to catch flak as soon as I need the tiniest accommodation or assist.