You just took the words out of my mouth regarding the brother's ex! If this is true and is a pattern, I do hope she tries to regain what she lost!
And if it's true, then it makes me wonder where they learned this behavior. I wonder if their father ever said you shouldn't do this, this is not how God would want you to behave. Maybe he did say it but grown Children tend to do what they want. If it's a pattern then the brother's ex was much luckier than Sheri and her boys. The brother's ex at least got out of that marriage alive.