What's the Etiquette on Bomb Shelters?

So, an aquaintance showed me his bomb shelter. Now I'm not sure Emily Post ever got around to this, but is that an implied invitation? Like, if the shit hits the fan, come on over. Other wise, it's kind of a dick move, I mean, just taunting me like that. If armageddon happens and Bruce Willis is unable (or unwilling) to stop it, should I just mosy over, or should I call first? What do I need to bring? Six pack? Hot dip? Is there an expected plus one? I mean, I'm not seeing anybody now, but I bet I could get a date to a bomb shelter at the end of the world.

Any help would be appreciated


S.O.L.