Please note: this entire concept was taken from a dream. No lucid dreaming was involved. Just wanted to put that out there. I can only hope that this could branch out to some great stories.
Everything was fine before the aliens came. They found humanity's never ending hunger for pleasure disgusting. They wanted to punish humans forever as a lesson. They did, of course. As the aliens did exactly, a message was sent to every human being as a final warning. "NEVER DARE TO PLESURE YOURSELVES AGAIN, AS YOU ALL ARE NOW CURSED TO TRANSFORM INTO PETTY ANIMALS IF YOU DO SO. YOU WILL FORVER DISPISE THE ONES WHO HAVE, LOVED OR NOT. AND NEITHER SHOULD YOU DARE PUT ON CLOTHING RELATING TO AN ANIMAL, FICTIONAL OR NOT. YOU MUST ONLY HAVE A MAXIMUM OF TWO CHILDEREN. ANY MORE THAN SO, AND YOU SHALL BE TRANSFORMED AFTER THE THIRD'S BIRTH!" And with that shaking speech, the aliens left, most likely never to return again.
Some did not heed the warnings of the aliens, however. Most of these few were only turned into anthropomorphic. Some turned into mythical or fictional creatures, never bigger than the average human. Few weren't so lucky. They became animal, head to toe, leaving every bit of humanity behind without warning. Some who still had lust for one other changed only slowly with reversable effects, unless it went too far.
It was on the news around the globe, showing furries becoming furry, and people turning into the animal of the fur coat they were wearing, real or fake. This caused animal print clothing to decline due to the curse. People were paranoid, and privacy no longer existed. The new anthros were forced to start civilizations in hidden places for their food, thanks to the people who wouldn't let them apply for jobs, let alone sell them even the most basic of ingredients.
Several decades had passed. Everything calmed down, but has never stopped. There were a few here and there, too ignorant to listen. Rarely anybody was willing to put on one of the clothing items with printed fur. And what made it more discouraging was the prices. Always more expensive than brands like Gucci and Supreme to try and keep people from wearing them. And lust was almost never a thing for the ones who remained human. Even the word 'sex' made people dissatisfied. But they knew they had to do it if they wanted humanity to keep living on, hopefully to see the day when the curse is lifted by the same ones who started it.
Now that that's out of the way, where would you like to start? Or, if it fits your taste, who will be the stupid/willing one?