Buckwheat and Bowties

Ever want to eat with someone and he/they/__/she will ask you to list options? So you go down a list of cuisines based on country. Then, when you mention a vegetarian place, he/they/__/she will ask, "You're not vegetarian, are you?"
Why would anyone think that? Does a person have to be vegetarian to want to eat in a vegetarian restaurant?
Then the omnivore or carnivore might say, "There's nothing for me to eat there."
Strange.
Has that phenomenon happened to you?