Just informing him that only careless people would leave their guns out in/on a place where a kid could grab them. PC 25110; PC 25200 It can wobbler crime(misdemeanor/felony) to keep a concealable firearm in a place where child can access it easily(on a table, in a drawer, in a desk, ect) and that weapon is either loaded or unloaded and causes death or great bodily damage to him self or someone else. It can be a misdemeanor if the child causes injury that is not great.
It is also a misdemeanor if that firearm is taken off the premises loaded/unloaded.
So if you are a law abiding citizen, most likely your rifles and handguns will be locked in trunk or gun safe.