Preferring one parent to the other is a normal stage of your kids development. While this can be quite hurtful for the parent who is being excluded, it is helpful to remember that it is usually just a phase which will pass soon enough. Find out what can you do when your kids tend to prefer one parent over the other.
In our busy lives it often seems quicker and easier to give children instructions and replies of Because I said so or Do it now! However rewording your requests with phrases that show interest and promote involvement will encourage children to cooperate more. It helps children feel listened to, and in time they will start listening too.