My friend wont let me talk to her friend whom i like

Julia
So theres a boy who i find very intresting, i think that he kind of likes me to, and we have made out and talked quite much the last couple of months. The boy is also friend with one of my closest friends. She doesnt want us to see each other or talk because she feels left out and finds him attraktive, although she had sex with his best friend and she is seeing another boy now. But I told him that we cant see esch other which he things is very unfair(and so do i) but i really like him and would like to see where things goes! I have tried talking to her about it but she never wanna talk about it because she feels bad for keeping me from seeing him. What should i do???