Blame (from The Ethical Slut)

It is always tempting to respond to a major relationship conflict by assigning blame. In childhood we learn that pain, in the form of punishment from our all-powerful parents, is the consequence of doing something wrong. So when we hurt, we try to make sense of it by finding somebody doing something wrong, preferably somebody else.

… What is impportant to remember is that most relationships break up because the partners are unhappy with each other, and no one is to blame: not yoou, not your partner, and not you partner's lover. Even if someone acted badly, or was dishonest, your primary relationship tends to end due to their own internal stresses.
- Ethical Slut