I love using my reusable coffee cup, especially since covid, as so many places around me seem to have defaulted to providing disposables only, even if you're sitting there to drink. However, when I am out and about for a weekend of shopping or a day out on holiday, I don't know what to do with it once I've finished my coffee. Sometimes I want a second coffee in the afternoon, but my cup is in the bottom of my bag with grimy milk and chocolate powder from my morning cappuccino. Is it weird to ask the coffee shop to rinse it out? Is it too gross to do it in the loo? If I'm in a pub and getting them to refill my water bottle, is it odd to also ask them to rinse my cup? Genuinely curious as to others' opinions.
P.S. I also have a weird thing about drinking out of paper cups (and eating with wooden cutlery), so it's not solely for altruistic environmental reasons!!