His frd a big problem?

me and my bf love each other a lot.my boyfrd's frd stays with him.and does not allow him to tak to me.he is always interfering.he doesnt like our relationship.i taked to my bf about this problem but he says he cant leave him as he is his best frd.and says me to coperate.hw should i coperate wen my relation is getting worse bec of his frd.i m v disturb.plz help