Yeah, I learned this one too. One of my roommates has been in the Navy for a year now, and he would have never shot a gun if it weren't for me. He's a really nice guy, but a bit of a "momma's boy" if you will. His dad was a police officer and apparently didn't like guns, only had his duty gun, and never took his family shooting. When I talked about moving in, I told him I had guns and they'd be in the house. He talked to his mom about the issue (She lives in MD and we live in FL) and requested that I have locking cases for my guns. I said, sure, my cases are lockable. Then when I moved in, he told me to store the ammo in a different place than the guns. This was when I had to take a stand. He had shot my guns before; I mentioned that we both were 22 years old and knew how to operate them. There aren't any kids in the house nor do we know anyone with kids. Guns don't go off by themselves, and putting them in the same room as their ammo is not inherently dangerous. A few months later I got my 1911, and a safe, which apparently made him feel a whole lot better. Yet he didn't comment on our other roommate keeping his loaded Beretta in a drawer.
Yesterday I came home with my Saiga 12 and the 12 round mag for it. Both my roommates looked at me funny, and then the one guy said "*** do you need 12 rounds for in a shotgun?" My reply, "I don't, but why not have 'em?" Then he proceeded to lecture me on how his Beretta 92 in .40SW loaded with FMJ would be more deadly than my Saiga with 00 buck. He had been drinking so I'll assume it was the alcohol talking.