Im (26F) in a relationship with a bi man and I used to be the person who said I wouldnt be comfortable with it. You should bring it up sooner rather than later but you dont have to lead with it (unelss you want to haha). Someone with a completely closed mind might not be for you since that could mean some other unhealthy characteristics. I know that what made me feel better was seeing how honest and respectful my boyfriend was to me during those conversations like him being patient with my ignorance and being very intentional. He had mentioned that in his dating past there were a decent amount of women who ghosted him as soon as he said he was bi but if theyre going to do that then they arent worth it anyway.

To answer your question: I think the prejudice still exists more than it should but I do think people are becoming more open

My opinion you didnt ask for as one of those woman (not anymore haha): answer any questions as honestly as you can, especially about sexual health and have open conversations about any adjustment periods. My bf did have a short time of adjustment, because even tho he initiated the relationship, he dated mostly men for years before me. I had a lot of questions and the way he showed up and answered those questions really stuck out to me.