Help with ex and mom 😞

So my ex has recently come back into my life and things have been going very well. We’ve gone out on a few dates and as much as there are things that are the same it feels different in a good way. But there’s a very big problem with this and it’s killing me. My mother literally hates her she already told me she doesn’t want anything to do with her and she just doesn’t want us together ever again. I think my mom thinks she may have turned me bi but I’ve told her that I’ve known since 3rd grade. Anyway things are very heated right now between me and my mom and her and I just don’t know what to do. I don’t know....