This may be influenced by the story of Lot who impregnated both his daughters (with the typical alcoholic excuse that they supposedly first got him drunk and supposedly seduced him. However, recent studies who that even when people drink to the pint of blackout, they never lose their sense and knowledge of the difference between right and wrong, so the biblical story doesn't hold up. Lot was an inncesttual dirty old man).
Coming soon to a nation near you: the Woody Allen Law.