Funny, I recently went through the same thing too.
Don't cry over other people, they are not worth it. If you're nice to your new friend, and your friend's buddy, you don't need to feel insecure, it's their fault for not opening up to you.
I believe that if you treat your new friend okay, your new friend will see that their other friend is being a dickwad, and will probably say something to them. Or the dickwad will come around and see hey, you're actually a pretty good friend to them too.
A friend isn't a friend if they believe the gossip of someone else. ^^ Chin up!
I had a similar encounter i don't usually go out what people call us is otaku but I went with my middle school friend on a gathering and one of her friend started picking on me she even called me lesbian and clinging otaku girl and I felt hurt cause my friend didn't tell anything to her
just wanted to spill some feelings not manga related sorry
made a new friend recently, been having fun talking to them
but their friend hates me to the core no matter what I do :'3c
kinda feels like crap when you're disgusting to them ;;
i wanna cry :'3