I bought a soda at a fast food place (B Good) that has a fountain set-up with quality sodas. I forget the maker, but it's all cane sugar, natural flavors, gluten-free, etc. I chose the root beer, prompting the young woman behind the counter to remark that the blueberry is her favorite. I replied that I'm not a big fan of blueberry sodas, as they tend to be sweeter.
To which she said, "I like it, but I'm a girl."
I froze in place as my brain tried to process the amount of WRONG in that. Neither her tone nor her face/body indicated she was in any way joking. Approximately two years later (which was only a few seconds in real time, since my beverage cup had not overflowed) I managed to fumble out, "I don't see what that has to do with it."
And promptly felt terrible, because there is really no scenario I can evoke in which it's totally OK for random older white guy to be pointing out sexist assumptions in the speech of younger female persons.
Dear readers, what would you have done?