Cheater, Cheater, Plastic Eater?

Over a dinner at Max and  Erma's of cheese fries and a salad (oh yeah - it all balances out) Harry and I were discussing an acquaintance who had cheated on their significantly hotter-than-they-deserved other half. 

And that got me thinking about a cat I had named Corey. 

He was - to say it blunt - freakin' weird. 

First of all - he was forty pounds, round as a basketball and loved nothing more than presenting his belly for all the world to pet and then, just when your finger tips would lower onto the purring mound, he'd wiggle, jiggle and lash out at you with his saber-tooth inspired teeth.  

I still have scars.

But I digress. 

Corey was an interesting kitty. He was orange and when we found his scrawny butt at the pound he promptly climbed the backseat of the car, squatted and defecated in the window for all the world to see.   This attitude would prevail for the rest of his life.  

His favorite thing to do, more than eating through the side of a new bag of Meow Mix, was to climb, face-first, into a plastic shopping bag and press his face to the side.  

For hours on end he would lick the bag, pink tongue flipping from one end of the "Wal" to the other side of the "Mart."  We half-feared he would suffocate himself but due to the fact that we liked having five fingers on our hands, we let him lick the plastic bags as he saw fit. 

The vet, when we finally called him, laughed and said "Well, he must be getting something from it that he thinks he needs.  Something his diet is missing."

So is this what people do when they go outside their relationship?

Are they just looking for what's missing?

Trying like hell to find a way to get what they think they need?

Or are they just bunch of bag-lickers?