Some background story is needed for this. In my friend group there are about 8 people. I (19F) along with my bestie of 15 years, let's call her Yumi (19F) are the only girls in our group. The rest are guys from ages 18-19, but they're all still a year behind me and her. One of them, let's call him Theo, is the one we've known the longest. We've been very close friends since middle school, and we befriended him first which led him to introduce us to the rest of the guys. Travel back to a few months ago in mid-november ish. One of the guys in our group, the second youngest who we'll call Jim (17M) became very attached to me. Jim and Theo also are very very close, often reffering to eachother as their Gojo and Geto. Everyone in the group strongly suspected he had a massive crush on me even though I've always very clear about the fact that I won't ever feel attraction to men younger than me. Especially the guys, they're like my found family. Unnfortunate for me, Jim chose to be blind to everything and even decided I was to be his personal therapist despite my obvious discomfort with it. His mental health is very very bad, and he's been going to therapy for years, but no one in the group has ever seen any improvement. He usually threatened to end his life, and the threats were basically monthly. He would always randomly throw this crisis at me, not even giving me time to prepare emotionally or mentally, so it always hit very badly for me. The most recent one in February was the worst so far. In all the times he's threatened to permanently leave this earth, he's always been home, so I was able to ask a family member of his to check up on him. This time, he was missing. I panicked, as he blocked everyone else in the friend group and even his family. I was the only one he was talking to and he was saying some very terrible and frightening things. I called the police because I didn't know what to do. They tracked down his cell phone and eventually found him and brought him home to his parents, but I was still very shaken up and distraught. That's where Theo comes in. Theo and I are very very close, he's called me his sister and I've called him my brother. We've even talked about him, Yumi and I moving in together once we all graduate from college and start our careers. He drove over because he knew I needed support. He took me for a drive, held my hand, bought me ice cream and kept me distracted. He told me that he hates seeing me cry and promised that he would never hurt, or leave me as others have done in the past. This made me feel like we were stronger than ever. I have since blocked Jim and expressed to Theo that I no longer feel comfortable being friend with him. It was even Theo's idea to do so and he supported me leaving behind Jim despite still being friends with Jim himself.

Now back to the present. Theo has had his fair share of fits. He's known for making group chats excluding others from our group just because he doesn't like that certain someone in that moment. He's also known for randomly ghosting someone in the group because they've done things to upset him, but he will never explain what said person did wrong because it's "petty" and he's embarrassed to say so. So his amazing and totally correct response is to completely ignore that person as if they didn't exist. I'm talking about if him and the person he's mad at are in the same voice call, he'll completely ignore that person even if they call his name multiple times. He'll do it in text chat too. Better yet, he'll make plans including everyone but the person involved. Sometimes he'll go out of his way to blatantly make the plans in the chat where everyone can see and just purposely not ask that one person. He's done this to me multiple times and has hurt me deeply alot. I'm a forgiving person, so I've welcomed him many times in the past. Even when he randomly decided he "got bored of us" (something he quite literally told Yumi before), I reached out to him after a month of him leaving because I know him and I know he had absolutely no other friends. He was also starting college that month, the same one as me. I know he struggles alot when he's alone, and even though he was the one that yelled at everyone and left, I gave him the chance to redeem himself. I convinced everyone to give him another chance, since it seemed he really did change and eventually everyone welcomed him back.

Enough background. This current issue all pretty much started when Yumi got a boyfriend. You would expect that Theo got angry because she completely stopped talking to us, but the exact opposite happened. Since she isn't weird, she still hangs out and plays games with us and did not cut us off completely like some people do when they get into a relationship. Honestly everything with her is completely normal. Now more recently I made a new friend. My new duo (23M) is an online friend, so it's not like we hang out every day. I met my new duo during a fortnite match with another friend as he introduced me to my duo. He's pretty chill so we play alot of fortnite and other games. Now before that, me and Theo used to play duos alot. We used to match Godzilla and Miku, since in every universe, they're friends. Theo and I like to say that's us. Now before any of you say anything like "that's very obviously leaving Theo behind to go play with the new guy" it's literally not because we invite him and other people to play all the time. He's the one who randomly stopped responding to the pings. He also stopped responding to dms too. I've check in on Theo a few times since then, asking if he was alright or if he wanted to play Phasmophobia like him and I always do. Radio silence. So naturally, I think he's in one of his moods again. When you text him when he's upset like this, it takes him about 3-5 business days to respond otherwise "he'll say something he'll regret." I ask my friends about this personally and it turns out it's only me and Yumi he's acting like this with. He's even regularly talking with others in the group that's he's had major issues with in the past. During this entire time, I play with other people and my duo. I knew he'll come to me when he's ready to talk. Eventually he did, and messaged everyone in a private group chat of the original 4 of the friend group which is me, Yumi, Theo and another friend Cas (19M). He messaged that neither me or Yumi cared about him and that we never tried to reach out or talk to him the entire time he was silent, which is obviously not true. I sent the screenshot of the three times I reached out to him and how every time he left me hanging. He snapped and began listing reason after reason on why I didn't "miss him enough." I kid you not, one of the reasons was "miss me enough to not invite me to a session of Repo" which we definitely did on multiple occasions. And what's even more weird about that, is that the first time Theo and I ever played Repo, was with eachother and he could only go for an hour before he got severely motion sick, so I don't understand why he would want to play again. I gave him genuine answers to each and every reason, which were genuine and very passive. I made sure of it. Yumi also wrote a paragraph explaining she also didn't know what was going on, and that she was very confused on why he stopped talking to us first, and is now blaming us for everything. His response was "alright guys, I get it. You're better off without me" and immediately left the group chat and blocked both me and Yumi without even giving us a chance to understand what was going on. It all happened so fast that we honestly thought it was some sort of prank. But hell, a week later and he even started unadding us on different platforms too. Yumi and I genuinely don't know what we did to deserve this. But yesterday we finally got the reason.

Theo texted our other friend, let's call him Garcia (18M), and basically told him everything. The way he was talking was as if he wanted to paint me and Yumi as the bad guys. Thankfully Garcia had a notion that Yumi and I did nothing wrong, and sent us the screen shots. When I tell you I crashed out when I saw the messages, it's probably a severe understatement. Theo is doing this to both me and Yumi quite literally because we are playing fortnite with other people, her being her boyfriend and me being my new friend. That's his reason. He apparently doesn't have a problem with us making new friends, he has a problem of us doing things we do with Theo, with other people. Is this larp? are we larping?? God forbid a girl play games with someone else. He's still talking to everyone else in the group chat as if nothing is wrong, because technically, he has no beef with anyone else but me and Yumi. I'm so fed up with all of this and everything is just so frustrating for both me and Yumi. I think our other friend Cas sides with Theo as he texted us saying to not hold this against Theo. Are we being for real. Anyways I genuinely am just so confused and angry. I don't think staying friends with Theo is not the best course of action. Nonetheless he's still very dear to my heart and I still consider him to be one of my very best friends. It just frustrating to think this is how it ends. A month ago I even started crocheting him a gift for his birthday, which is in next month. It was gonna be a plushie of Miku and Godzilla. I thought that because of the whole thing with Jim, he wouldn't do this to me anymore. He promised that he wouldn't do these kinds of things anymore, because he knows how hard it is for me to lose people I care about like this. My friends are my everything. I know he can be very caring and emotionally understanding, the whole situation with Jim proved it but he still did this. What do I even do? Holy fart bro.

TLDR trio member got jealous of me and other trio member when she and i started playing with new friends even though we tried to include him but he basically excluded himself, and now blames me and other friend for everything and blocked us (bro is pushing 20 by the way).