When a child makes a complaint to your spouse, don't be the one to "second it" (as in, "Ya, I agree with Junior - you are on your phone way too much."). Doing this sort of thing is called "triangulation." For one second, you and your child will be on the same team (against your spouse), experiencing a moment of bonding. While that may feel good, it can cause enduring harm for you, your marriage, AND the child. There is no need for you to get involved in a conversation your child is having with your spouse. Any complaints YOU have about your spouse, should be made in private.