I might be being dramatic but this has been really bothering me [Rant]

The other day, a very good friend of mine who is bi-curious made the following joke to me:

“Well you would have been killed in the 18th century. Witch. You’re a homosexual. They would have killed you. Burned you alive.”

The fact they said this to me makes me want to cry. Stuff like that isn’t a joke to me. Over the past several weeks/months, that person has made a lot of jokes about me being a lesbian that I am uncomfortable with, and some of them like the one I just listed feel really awful to hear. I really care about them and value our relationship, and I think these jokes might be the result of them figuring out their identity, but I don’t know. I’m super non-confrontational and hate situations like this so any advice on how to tactfully and kindly let them know I’m not comfortable with those kinds of jokes would be greatly appreciated.