My wife loves my muscular ass and enjoys putting her tongue inside of it. It feels pretty good, but it isn't my favorite thing to do and it only happens once in a while.
However, once while deployed overseas, we were ported in Greece (I think it was Greece, I sometimes get the numerous places we visited confused) and I was getting my dick sucked by a hooker. She couldn't get me to cum, so she stuck her thumb up my ass while she blew me. I came.