My bf is jealous of my bi friend. What to do ?

I’m bisexual myself and he knows it of course. I’ve met my friend couple months ago. Aside from the fact that I am in a relationship, she’s just a friend, not my type, not her type. We basically only talk anime and video games anyway. But she’s fun.

My bf is getting super jealous of her. We’re long distance and his issue is that he has never heard of her up until a month ago and now we’re going out once a week at most.
Thing is we’ve only been dating for three months and a half. Aren’t adult friendships basically seeing each other once in two months and then promising to go out at some point but never actually do that until three months later ?
Moreover, most of my friends in my city left to start jobs and internships, so she’s basically the only person around…

I believe I have explained everything as I should and reassured him in the best way I can. I can’t NOT see a friend that I really like because of him.

Idk, does this sound normal to you guys ?