I fucked up big time

I’m 16M, and my brother is 17, turning 18. He has a friend named Z, who is 18M. We’re all Chinese (relevant), and we hang out with a small group of friends, including H (16M), D (16F), and J (17M). Most of us met Z online, and he was someone I wasn’t particularly close with but got along with fine. This Friday, we decided to meet up in person, which ended up being a huge mistake.

The Incident:

At the Restaurant: We met at a restaurant, and while we were eating, J made a racist joke (he said something because his dad is Chinese Muslim). I responded with, “bro what if the waiter was Indian Muslim?” not thinking it through, because the waiter was Indian. It was very insensitive on my part, but I don’t think I was racist

Bowling:

After eating, we went bowling, and me and J were pretty obnoxious. We didn’t really care about how we were coming across. I didn’t think much about it.

Bus Incident:

When we dropped off our friends, there was a moment when J plucked D’s white hair (she asked him to do it), and Z brought this up as “sexual harassment.” I still think it was just weird, but apparently, Z thought it crossed the line. Also, there was some weird comment about D sitting close to H on the bus, which I didn’t really understand.

Z’s Reaction:

That night, Z went on a call with my brother and said that J and I were racist and obnoxious, and that the hair plucking thing was sexual harassment. He also called us “classless” for being loud at the bowling alley. Then, he said something like, “I want them to face the consequences of your actions” and that we wouldn’t learn otherwise. He made this remark after my bro asked “why don’t you tell them if you’re unhappy about it?”. This felt weird and pretty self righteous for someone who’s 18 and acting like an adult.

The Aftermath:

My brother and I decided to confront Z and talk things out, hoping to settle everything. When we tried to, Z was quiet and left the call quickly, saying he had to sleep. Then, he removed me and my friends from all social media and even deleted his Instagram. My brother tried to apologise, and Z acted distant and somber. Z didn’t want to talk anymore, and now my brother feels like he caused the situation and is blaming himself for it. My brother was upset and cried for 15 minutes straight. Z blocked me, and I feel bad for my brother, who is still sniffling and blaming himself. He’s playing games with J, but he’s a total wreck. I feel like Z is an immature and selfish person, like I genuinely don’t even know why he made those remarks in the first place. If you’re unhappy, just tell us. Idk what was the point of that remark, which was just plain weird

TL;DR: I’m 16M, and my brother (18) has a friend, Z (18), who me and my friends met online through my bro during his secondary school days. We all hung out in person, and things went south. We made some insensitive comments and acted obnoxious. Z called us out, said we needed to face the consequences, and accused us of racism and sexual harassment (over a weird hair plucking incident). He blocked me and my friends, and now my brother is upset, crying, and blaming himself. I feel bad for him but also don’t know what to do. I would appreciate if someone could give me some advice.

Edit: I also want to add that Z has been friends with my bro for almost 6 years. Giving me advice like “friends come and go” is true, but it really doesn’t help with the situation. Thanks

Edit2: my brother is turning 18 this year, so I’ll just say he’s 18, because apparently a one year age gap between siblings is weird? Also, this was my J, H and D’s first time meeting up with Z. Ive met Z irl through a bbq hosted by my brother, so i kinda know him. Z most likely does not have a crush on D, and speculating that is just kinda weird imo, especially considering their ages