Teenagers should always tell their parents the truth

It might be a good thing for kids to always tell the truth to their parents, but it´s merely impossible.
One fact is that parents don´t always understand the situation and always think they´re right, making it hard for the kid to tell the truth in certain situations.
I think that if parents tried to uderstand and if kids were a little more expressive, then there wouldn´t be any problems caused by lying.