Companies differ on their definitions for principal, casual, secondary, primary and occasional driver. Because of this you will need to speak to your insurance company's agent to find out if your son needs to be moved up to the primary driver or if your household will be insured properly if the policy remains as is.

The risk you take if you do not speak to your insurance company and follow any changes they suggest is that they might be able to deny future claims. They could be able to refuse if their definitions of primary and secondary drivers were abided to. You will want your son and vehicle properly insured for any incidents that might occur so it is wise to just check with your carrier and make sure you are following their guidelines.