I love it. The first time a girl ever licked my ass, I was about 25. Oddly, it was after we had been out on a farm all day together at a party sweating like crazy. Maybe that's what she loved, but when we got into bed, she went straight for my ass and licked it for about an hour. Almost every time we had sex after that night, she did the same thing. The first thing she would do is eat my ass. I sure miss her.
Then there was a LONG dry spell. I love licking ass, but not all girls go for it. Sometimes it makes them uncomfortable and the stop me. After eating one girls ass for about 20 minutes I asked her how she liked it, and she said "It tickles".
However, there are those that really appreciate it. One GF I had had never had it done before. She said it totally freaked her out, but she would fight to just go with it and let it happen, and it was like heaven. Another I had loved it. She would bend over and spread her ass for me and stick it in my face, then I would tongue fuck her ass.
I never really met that many women that were into licking my ass until I was about 40, then I ran into about 5 of them in a row, and they were always the ones that instigated it. Once used to finger fuck my ass while she licked it like eating pussy. One loved it so much she would eat me for hours. One was sucking my cock and I said "Lick my ass" and she tongue fucked me like a pro. I asked her afterwards when was the first time she ever did that, she said "Just now, you're the first". That was fun.