Am I too sensitive or this is alright?

So, I'm homeschooled and I'm finishing school this year, I live in Russia so people there are pretty much clueless about Judaism, and there was a math lesson and I had this one math teacher for a couple of years so we grew close and I showed him the sevivon I made and he looked at it, said it was cool and all and then said "what was that insult for Jewish people, again?" and I said I'd rather not repeat it because.. I know what he was talking about, and then he said the slur out loud and laughed at it.. I didnt find it funny or cool AT ALL, in fact, it kinda hurt me if I can even say this, I mean, WHY would he say the slur??

And then he asked me if I knew how this slur appeared and I said I knew and then he proceeded to explain that "Jews were merchants and they're so greedy they were called that slur", and then he proceeded to say that "you dont have that much of a slur blood, do you?".. Uh, I think it wasnt good at all, but I didnt say anything because I think he wouldn't understand why it hurts people, he's pretty old

And I'm not sure if I'm being sensitive little woke person there? I mean, I dont think slurs are cool, like, at all.. But am I just being sensitive? It did hurt me after all (plus then he proceeded to ask me why I wont celebrate the new year and when I tried to explain, he started ranting about how I should respect all religions and all, but I didnt insult anyone, I respect everyone and I didnt say anything bad)