"I'm sorry, {_name_} the laws of the state of NJ place pretty severe restrictions on where it's lawful for me to posess and store my firearms. I'd suggest that if you're going to be in the business of giving advice on this topic, that you do a little more research, before you get someone less well informed thrown into jail."
That is too cool! Good for you, man! I love it when a pompous, snide little know it all gets put in their place!
When I got my first handgun, my anti Mother refused to let me keep it in the house. So, I rented a small storage unit (one of those open 24 hour places) and kept it in there. It was a pain to have to go get it out but it was still worth the hassle. I would rather have a friend do that than take responsibility for someone else's property. If it gets damaged, stolen, whatever there is the risk for liability (just establishing the liability under the circumstances would probably cost an arm and a leg, not to mention it may not be legal) and may destroy a friendship. I would politely refuse, and state the above as my reasons for not wanting to do it.