I am an undergraduate research assistant in a biology lab. I was having an informal conversation while working at lab with my professor and a colleague of him. In the middle of our conversation, my professor passed a racially insensitive remark at me (I can reproduce here if someone wants to know). However, he realized it and walked away immediately. I am very upset.
But after few hours, he came back and he was conversing with me like nothing happened, but I am still upset. Can you all tell me how to handle this? My options are to ask him if he did that unknowingly or to keep quiet. But I really want to know if he feels sorry for what he said. I really don't want to complain to his superiors, but I want him to apologize to me for what he said. Is this unreasonable? if not, how should I go about dealing with this person?