I guess it would be more useful asking yourself what you got out of this friend being in your life?

Theres a book called friends and enermys how we keep people in our lifes that we know we dont really want as friends, but rather they serve a perpurse, we can "hate" them where as if it really was someone we cared deeply for and were kind to us, then we cant "hate" them and we all have a need to love and hate.