Leenism
When you can't eat a product of an animal with the meat of that same animal, combined.
Can't eat Cheeseburger, (cow meat with the cheese that's made of cow's milk)?? This is leenism...

Can't drink Milk shake with burger?? Leenism.

Can't eat Chicken with egg? Leenism.

Can't eat Goat meat with goat cheese? Again, leenism.

Can't eat Fish with caviar? Leenism.

All these are examples of what is known as "Leenism"