Many moments in parenting seem unavoidable. Your preschooler will throw fits. Your third-grader will try to get out of doing homework—even if it means lying. A budding tween will dish out insults. And a teenager will simply take off for who knows where. At each stage, they are trying to test your boundaries (and sometimes your patience). While this may be a natural part of growing up, that doesn't mean any of these actions are acceptable or...