My life is realyy messed up right nowhelp?

ok so theres a girl i really like who already has a bf and my best friend talks to and hangs out with her all the time. evrytime i call he hangs up on me cause hes on the phone with her because hes hangin out with her. If me and him are hangin out and shes calls or him in on the phone with him he either walks away to talk to her or hangs up on me again. im afraid im startin to lose my best friend for a girl that isnt even his gf. the worst part is that i like her alot 2. plz tell me what to do