Blended families can exacerbate issues that were already present before the families got blended. If a kid mistreats his parents and they don’t do anything about it, chances are he’s probably going to treat his stepparents and stepsiblings with as much cruelty as he treats his parents, if not more. It’s difficult enough for kids who are usually well-behaved to integrate into a completely new family structure, let alone those who have never had negative consequences for their bad behavior to begin with. Parents need to be sensitive to the difficulties of blending their families, but they shouldn’t enable their kids to treat their step-siblings any way they want. That’s how you get the ugly stepsisters tearing up Cinderella’s dress before the ball! And those divas were full-blown adults! If Lady Tremaine had nipped that in the bud when they were teens, maybe her daughters would’ve had a shot with the prince.