If it's a friend I bore them about rep/Franken/gen watches, the definitions and the subtleties which I'm fascinated by, because they are friends they tolerate me and politely wait for me to stop talking!
I've never had anyone else ask me. If it was someone who seemed genuinely curious I may well talk to them in the same way as a friend, maybe even refer them to one of the sites. If someone asked in a confrontational way I would not be polite, whether I was wearing a gen or a rep makes no difference.
I only wear reps that are believeable for me, Rolex and Panerai, stainless steel, a nice strap too I think makes a massive difference. I was recently looking in the window of a panerai ad and mine looked more real than all of them due to my lovely handmade strap! I saw a young lad wearing a full gold rolex datejust 2 yesterday, one glance and I thought GTFO!