Some random dude walked up to me while I was waiting outside a food place for my food and asked me this question.
I said “no, I dont give out random favors” and something along the lines of that’s sus.
Is it rude to say no to random dude that asks for a favor?
Not my experience. I think “can I ask you a favour” is a normal opener to a request, rather than splurting out the whole request right away.