Long story short, i met some people over discord a few days ago due to a similar niche interest. We talked for a few hours today and my sister kept on wanting my attention but since this interest is also somewhat intelectual i had to really concentrate and kept on telling her i dont have the time right now.

Now after about 3-4 hours of texting with them they started a voicecall and i wanted to join as well but my sister said if i join it she'd embarass me. So after contemplating it i warned them over text and joined. I have to say one of the girls was really pretentious, but i stayed and talked, though my sister found her pretentiousness annoying and started laughing and stuff. The pretentious girl then got annoyed and her and my sister basically started cussing each other out, which was very embarrassing for me since i was just excited to meet new people and the other people seemed really nice. I then muted multiple times so my sister would calm down but each time i unmuted the pretentious one would say something provocative ( like telling my sister to shut up and telling me to make her shut up) so my sister would get angry again. It escalated and i left the call, so did everyone else and now the mood's ruined. My sister left my room and told me she would have defended me and that i always sell her out, and whatnot. I told her that she embarrassed me and that if she kept quiet the pretentious girl would've eventually calmed down. Now neither the group nor my sister will talk to me anymore and im really pissed because i was happy to make some friends. Am i the asshole?