So many younger people get onto these Discords these days and create these friend groups that feel so tight and so important. They can even ignore actual people in their own area that they love in favor of someone who lives in Morocco or Japan or something. The well-being of someone thousands of miles away becomes so important. And with the immediately available phone screens, people can come to feel everything is a kind of emergency and needs to be dealt with right now!
But like Bobbi said, these servers are really a terrible way to communicate. People behind a screen can, even when trying to be "good," dash off inappropriate messages, or get in cliques, or gang up on someone, and then there might be someone who gets bullied, and they'll go and start their own Discord, people take sides, and others will beg them to come back, trolls will be snide and hateful and hurtful and need to be dealt with, on and on, ad infinitum, ad absurdum. Lots of times people who are very young, with next to no social skills, pretty much live on their Discords.
Your long-distance partner Bun seems so real to you. She is a real person. But you aren't dating her in any real sense. Chatting with her from behind a screen is completely different from actually dating in real human space. She might seem completely different in person. Maybe not right away, but if you started living together, or nearby, she might be even harder to get along with than she is now!
I have a younger family member who has started all three of her serious relationships online. Then she's impulsively moved to live with them (individually, over the course of 15 years or so). Each and every time, after a year or a bit longer, the relationships have gone downhill. The partners have turned abusive.
I've begged her to just date locally. She's in her late 30s now. She is still on these Discords with friend groups from all over the globe, and there is still the gossip, the "emergencies," the shifting loyalties, people who self-harm and cause a fuss, the ignoring of real human spaces in her own home or town or state. She has lived far from home in the eastern US, flying off to the American Southwest, the deep South, and a European country. She also fell in love more recently with a person who claimed to be in college, but was really in high school!
Ugh. I am just so jaded about this whole kind of thing.
Back to you. Bun never needs to move or live with you or Hub. Fox doesn't need to move or live with Hub or you or Bun. Anyone who wants to can move NEAR you or Hub, and get a place of their own, and start by dating normally, each person having their own space, their own bed, etc., just dating a couple days a week for a year or two, to see how people really are in real life (not online, and not as a romantic out of town guest on their best behavior). Co-primary status needs to be earned. You can't just be online partners for X amount of months or years and get to be a co-primary. That may seem harsh to a person like Bun, but it's just the way it is.