Well, thank goodness for volunteers! ;-)
HungVet, as someone who has played as a single for about half the time I've been doing this, I'm well aware of couples who want you fulfill a fantasy and leave. I try to avoid them, because they are clear in their disdain and/or impersonal approach and that's not my ideal for a satisfying sexual experience. I suspect single men run into that even more and I continue to think that's driven by the needs of the other man. I can't say I totally understand it, but some of it clearly seems to be based in competition and probably has a biological component.
Anyway, at least for me, sex is great, but I am really picky about what couples bring into interactions with me. Which is why I mostly play with halves of couples rather than couples.
The issue of performance and the different treatment is partly mechanical. If men can't perform, it's kind of unsatisfying. A woman who can't get aroused has the option of faking it.

