His ex is crazy, but i love him, what do i do?

last week my boyfriend broke up with his ex, he asked me out on the same day that he broke up with her on. we have bin out before & i still really liked him, so i said yes. but now his ex, who i was quite freindly with before, is really mad at me and wont even talk to me. ive said im sorry & everything but she won't budge, & now she's startin rumours about me and all that, i realize she's angry but why do all this ?