Its funny how some things start. I, personally, am enthralled by how people think about and handle sex. I used to do all of the things Amanda did, save mix some of my games with sex. It does become a slippery slop. Eventually text, no matter how good, isn't good enough. It can get you excited and ready, but not really feel as though it delivers with the same impact it used to. This is compounded by the fact that some people are just better to play with than others, and after having a good partner others just don't seem as good. Once you move beyond text it can become extremely scary as well. Who is seeing what your showing, what will they think, and most importantly, what will they do with what you show them? And that becomes part of the thrill, if you plan on not becoming a politician or something.
Standard avatars can never be as good as text, but take it from me, be careful if words start seeming like they are not enough.