You know, I'm not completely sure if there is.
My parents have been good to me.
I'm the one that broke up with my only other boyfriend.

I guess it might stem back to school, the "friends" that would turn on me as soon as the winds shifted to where they should.
Backstabbing biting... *mutter*

But when it comes to romantic relationships, there's really nothing to explain the issue.
I suppose that "friendships" would effect (affect? I hate those words) your stability in relationships as well.