It has been discovered that there is a direct relationship between oral sex and cancer of the throat in pussies. Cats who enjoy a regular lick of their posterior are particularly sensitive to this form of cancer and it seems that human pussy lickers are too.
Scientists observing the furry pussy species discovered that whilst cleaning their rear-ends with their rough tongues they frequently ended up with fur balls in their mouths and this enhanced the chance of throat cancer developing.
After discovering this fact the scientists also did many tests on human pussy-lickers and it seems that "a rolling tongue does gather moss" after all and the moss has a tendency to stick to the side of the throat causing eventual cancer.
Throat cancer specialists are advising the human pussy-lickers to either give up oral sex or start smoking because smoking, although not healthy either, is better than having one's throat clogged up with hairy balls (if you're a woman it doesn't matter!).
As for our furry, feline friends, they don't give a crap after having one!