Nb friend and homophobic parents... advice?

I have a friend who came out as nb a couple years ago and recently changed their name. We grew distant after we moved to different schools but we’re trying to rekindle our friendship.(and I have a wee crush on them but that’s beside the point) Whenever I want to mention them my mom gets upset because she says I never had a friend named *chosen name* (bleeped for privacy reasons). And if I explain it to my mom she’s going to make me block them and stop being friends. She did that with my lesbian friend after a rumor spread that she was dating my cousin’s ex girlfriend(long story) because “oh no she’ll turn you gay or flirt with you and send both of you to hell”.

So to protect our friendship I have to use their dead name. But that creates a problem in its own because i know dead names are a big thing and I’ll have to tell my mom eventually. Every time I do it I feel so guilty. I feel bad when I slip up and accidentally say she, but that’s force of habit since I’ve known them since kindergarten. But I have to purposely do it and I can use they/them pronouns around my mom and she doesn’t notice but... I don’t know what to do. I’m in high school and my mom closely monitors my friends and where I am at all times. If I want to hang out with them, my mom will want to meet them, and either she’ll recognize them and use their dead name and get mad at me because they’re nb, or I’ll have to use their dead name and mom will go along with it. My dad on the other hand, is a wild card. He is really homophobic/transphobic and extremely vocal about his views on it. But he usually stays impartial with friendships as long as there isn’t a straight guy involved so... 🤷🏻‍♀️

I just... i need advice.