Someone you invest yourself in, for perhaps years, and they choose to betray you in hopes of driving you away (I think as a test originally) but then realize what they actually done and are too proud/scared to reconcile or admit they were wrong about you now that the deed is done.
And to your damage, if they had of not been so proud, not been so scared, you would have forgiven all but instead you are stuck with with your heart in a cuisinart, left on the chop cycle, when they walked away.....
And it helps even less when all of your friends hated her and area against you desiring to forgive in the matter.