Be glad your boss is not a hoplophobe. Rather than "spring it on him" by showing up one day, why not discuss it with him?
Does your work have lots/some public contact? That might be the reason he limits carry to CC. And yes, he's the boss and he can OC because he's the boss.
If you are stuck with CCing at work, be aware (you probably are already) that many tuckable CC rigs can convert to OC merely by putting your shirt tail where it belongs. Also, there are all sorts of vests that do not scream "Shoot me first/fly fisher who got lost in the parking lot/I'm from the internet" or imply that you have a chopper (2-wheel variety).