Will i get in trouble if i tell a kid his dad will spank him when he gets home and he doesn't want to?

Wrong, many reasons: This needs big help, so we'll start from the beginning. Spanking is the least effective form of discipline. Your pediatrician can help with time-out techniques. Discipline should be consistent, and immediate. There should be effective discipline delivered now. Transferring the duty to dad means you have no authority. I would work with your doc and break this down to get good effective discipline.