If anything, if you stay friends, eventually, he'll learn from you. He'll learn that there's nothing to "fear" or whatever from the LGBT+ community, because the example of the community that he'll see most will be you.
My best friend and I were talking recently and someone asked how we were friends... "He's clearly homophobic and you're talking about your Ex-boyfriend"... I paused for a moment... This is a curious scenario... And when I paused I thought for a moment we don't have to agree... Maybe he is against gay... maybe he doesn't like LGBTQ... And maybe you think he's wrong for that. But he's my family... He's the one who supported me when my boyfriend left. He's the one who's never left me alone when I needed him. He's my Brother... Not by blood but by my choice. And to me he's perfect. So I don't care how much he disagrees with my Lifestyle or how many homophobic remarks he makes... He still cares for me MORE than anyone else... And I love him... <3