Question: Why futas?

First and foremost, because they're intensely sexy! All the wonderful, sensual curves of a woman combined with that potent, highly-focused male virility. What's not to love?

But they're also incredible versatile. The same character can experience every aspect of an intense sexual relationship. Almost everything that's possible in straight, gay and lesbian erotica can be incorporated.

I also find that stepping slightly reality is very freeing as a both an author and a reader. It enables getting lost in the fantasy (without worrying about mundane things like the hospital trips that some of my scenes would probably require if tried in real life).