I suppose different words didn't come to mind as I was typing it, I honestly didn't put a ton of thought into it. "Slut" is a term I use for someone who doesn't fear enjoying themselves sexually or being ok with satisfying themselves. "Naughty" was used in the context of "doing something that is normally culturally taboo", not sure I have another one-word description for that (I don't like using the word "nasty" in that context) and "alternative" doesn't really convey what I was going for, it sounds a bit more clinical or sterile somehow to me.

Now that I put some thought into it, though, the woman that I would really find exciting is the one who is a "secret slut". Not one that appears or acts "slutty" (in the conventional sense) but one who is probably a professional or average member of society who you might run into at Target or Safeway and not suspect at all that she would enjoy an occasional gang-bang or enjoy sex involving simultaneous penetration of multiple orifices. I suppose that is part of what I found so arousing in the scene my ex and I participated in. The women were perfectly average people who, for the most part, were married and who were attending with their husbands or boyfriends and getting immense enjoyment out of being the center of attention of a group of guys where were also enjoying pleasing them.

In fact, the contrast is really exciting to me. The more reserved and typical and "all American" by outside appearance and the more "naughty" the activity engaged in (there's that word again but "alternative" didn't seem to fit there either) the more exciting I find the situation. So you have some guy who is a middle management type from some tech company with his wife who is on the PTA and maybe serves pancakes at a community breakfast on Saturday morning is enjoying a DP that evening after being fucked by three other guys earlier and everyone goes home to their life happy and satisfied ... until maybe next month when they do it again. Folks would often go out for breakfast after and we became quite friendly with each other in a social sense too.

I sometimes forget that people don't like those words.
In my last couple of relationships, "slut" was like a term of endearment, but, of course, that was because it was used in the context of the relationship that we had established, so she understood what I meant when I used the term. And she really liked it when I talked "dirty" to her, so I used it a lot.

It's true the word once had a much more negative connotation (and still does in some places), but times change and words take on new meanings in different contexts. The language is not static. But - it is that old association that still gives words like "slut" that little undertone of suggesting something transgressive.

I also like terms like "dirty" or "naughty", even though so much of sex is actually pretty completely innocent and natural n' stuff.
It can be fun to play with the feeling that there's something taboo associated with some things. Though I also appreciate that so much is out in the open and accepted these days.

There are other words out there besides slut and naughty, maybe headonist, pleasure seeker, multi-orgasmic, those just off the top of my head...I suppose it would only take a good thesaurus and some word smithing to make something fiting.