Lots of good advice here.
It happened to me - TWICE.
First time I had to kick a roommate out. First thing he told the police (he didn't want to go, thus the police) was I had pulled a gun on him.
Two cops were talking to him, two to me.
They all had a conference, my two came back and asked if I had a gun inside (I obviously didn't have one on me) and I said I did.
That was the end of that. They told the roommate not to return unless it was with a cop to get his stuff. I considered that to be a fortunate result.
Same roommate later threatened to file a restraining order which, thanks to Brady, removes your gun(s), at least till the hearing, for the very purpose of disarming me. Unfortunately, he did this via voicemail. Since, with voicemail, both parties to the recording are giving consent to be recorded, it's admissible evidence in Florida. So, luckily, he shot himself in the foot by making the threat that way.
I hocked (for half-price) my Beretta Cougar and got a different-looking gun.
Now I'm a little more careful about who gets to see my new one. The list includes:
1 - my mother.
2 - me.
Bottom line is, you don't necessarily have to keep it a secret you own a gun, though there are other reasons you might want to do that, but you should try not to let anybody see it until just before it needs to be used on them.