"Mom needs to mind her own business UNLESS there is abuse"
So, kids stop being their parents child when they are in other places and the parents shouldn't be concerned for their child when the child isn't with them? The kid ceases to be their parents business when they are away from their parents? How would a parent even know if there is abuse going on if they are supposed to turn a blind eye to what goes on with their child when they are with dad and SM?
The mentality baffles me.
So, the question is: Why do some SMs actually believe that a child is no longer their mother's business when the child is with dad and SM?