Haha, that's what I did today! I realized I have being going to this store for a long time now and we quite know each other now (he knows what I want to buy when I order, haha). So when I paid with my debit card, I asked him how much the fees are and if he heard about bitcoin. Wanted to tip him 10€ in sats but he first wanted to know what all this bitcoin thing is about.

Then we had a good talk about bitcoin and exchanged numbers so we can continue at a later time :) Was a nice experience. Best experience so far. He had many good questions about bitcoin.