This works just fine once the kid is old enough to make that kind of decision (for me, it was when I got my driver's license), but it isn't that simple when the kid is 3 years old, 10 years old, etc. There should be some guidance from parents while they are young, and that can cause conflict if two parents are telling them conflicting beliefs. Parents should have some kind of plan going into the situtaion of what consistent message they want their children to have.