You know the scene. You’re walking around with your girl friend and some dude starts saying “Young man! Excuse me!” Then you look up at him (kind of in shock) and he goes “Oops, young lady, sorry!”
What to do? I’m not often mistaken as a boy, but I know how it can leave you feeling. Some people can be insulted some feel indifferent or even a little proud… It really depends on the person, just like anything else.