My two grand-daughters live with their dad now that my daughter is dead. Their dad is a pathological liar and my daughter would get very upset when the girls "exaggerated" or out right lied to get out of trouble or for no reason but to get attention or to try to get out of having to do something. They are ages 6 and 9. What is the best way for me to handle their lying when I have them? It really upsets me as well.