 Why is it in the best interest for an Earthman to never lay eyes on a Venus dame?
Not enough to cause serious trouble this far out from Earth. Before the guys who'd brought the Venus dames to Earth could say anything they was taken apart too small to pick up with a blotter. Earth dames wound up by flying the Venus ones back where they come from and serving notice if one ever set foot on Earth again there wouldn't be enough left of Venus to find with an electron microscope. "No Venus dames allowed within fifty miles of their port. Any dame caught trying to leave Venus thrown to the tigers for supper. Same for any Earth guy caught around a Venus dame. Only tried to clear your mind about Venus dames so you could put your brain on your control mess.
 Because they would be so infatuated by the dame even knowing she would be their damnation.
 Because the Venus dames were thought to be only goofy tale set loose by some old space bum.  Because they would be so infatuated by the dame even knowing she would be their damnation.  Because they would be condemned to a Uranus moon for even looking at them.  Because of their dangerous nature.