I had a girl try to stick her tounge up my ass once.. I was like... well dear.. if your that brave then you go right on ahead.. but if something pops out or you get a little odor, I am not responsible..
I think licking a girls ass tastes like your licking a penny.. So I try not to do it that much..
Heck this is commonplace for the wife and I, (clean) ass licking is great HOT foreplay and we do it all the time! Only after showering and cleaning the area really good first! it's AWSOME!!!!!
Never had it done, but I perform it 2 out of 3 times when having sex. If I had the time, I'd probably lick ass every time I had sex. It's a big turn on for both of us. Makes em go wild and there's nothing you can't do after that.