Did you grow up with your stepmom?

I think with siblings there's always some rivalry, there's books about it. It can be baseless or completely founded. I find it frustrating as a parent, at the same time, I encourage both stop the nonesense or stand your ground and verbally stand up for yourself. At the same time, I can turn around and witness the closest of friendships. As though they are each others safe training grounds for the outside world.

But if you grew up in an environment where there was utter meanness trickling down from a viscious stepmom, then therein could lay a piece of your puzzle.