Many of the erotic photos I post are, sexually speaking, depictions of "intimate" (if mainly solo) moments. Pictures of me hard, sometimes pleasuring myself. It occurs to me that someone viewing those photos might get the impression that, because I post those photos publicly for complete strangers to see, I am "open" in such a manner that I wouldn't mind just anyone watching me in those moments as they actually occur (which is debatable, considering my exhibitionism). And, in other photos where I might be with another person, since I share those intimate moments with the world, one might imagine that I'm willing to share moments of that sort with just anyone.
But there is a barrier there - the barrier of photography. I choose which pictures to show the world, and through them, I can engage my exhibitionism while satisfying others' voyeurism, all the while without betraying the sanctity of my body. That is to say, I still get to choose when and where and with whom I behave sexually, and the fact of the matter is, my choices in those matters are much more restricted than you might think. You see, erotic artists are not necessarily sluts and whores, and I would argue that that holds for 'sex workers' of many stripes (individual results will vary).
Aside: In fact, I think the all-or-nothing assumption that if a person gets involved in erotic work of any kind then anything goes is generally harmful - it reflects poorly on the image of the sex industry as viewed by wider society, and it puts undue pressure on those who get involved ("you have to go all the way!"), or those who might have gotten involved if they weren't scared away by the horror stories they've heard (regardless of how true, or how common they are). Not to mention the fact that if you characterize the sex industry as sleazy, it will attract more sleazeballs. And you think that's a coincidence? It's a self-perpetuating phenomenon that the anti-sex puritans are all too happy to support - as long as sex maintains its sleazy image, their arguments which hinge on that "fact" will continue to hold water. Never mind who gets hurt in the process of ensuring that sex remains a dangerous, sometimes even criminal, vice.
Getting back to the main point of this post... If, for example, I were to post a photo depicting someone else touching me - you could not imply from that that I would give that privilege to just anyone I might bump into on the street (or even befriend). The fact that I show the world my intimate moments does not mean that I am "loose". I am essentially saying, "come, look at this", but I am not implying, "come, and join in". To do that requires passing a very thorough vetting process. ;-)
Although as far as pure fantasy goes, you're more than welcome to imagine whatever scenarios please you most. Just remember that those are your fantasies, and I have no obligation to participate in them. :-p