Pretty sure most people in the US are just more degenerate than anywhere else. It makes sense then that cons would end up being the spot to go to for such things.Never really heard of them, at least on my own local. Yes there's some attempts here and there, but not full-on orgy like you described. Maybe it does exist but they keep it super-wrapped, maybe it doesn't. Maybe it's just the american/europe/japan thing, who knows.