And I can tell your family is Irish because you called it Derry, not London Derry.
I don't know. Lots of people in England also say Derry (the few times they think about that part of the country at all). Even in Ireland most people in my experience are pretty chill about it as long as you aren't an ass about it.
I was literally almost assaulted in Belfast by accidentally saying LondonDerry when chatting with some locals. This isn't a theoretical, it happened just a few years ago. I calmed the lad down and bought him a beer. We then had a great time. The troubles may be over, but things are still not totally settled down.
