You take a pic. You angle it for your best assets to show. You write a short piece. It’s hot sweaty sticky and delicious. You make these public, you share. Do you care what the viewer or reader does with them? Does it turn you on to know that you stimulate? Do they ask you for permission bringing you into their pleasure? Does it humiliate you to be reduced to their masturbation fodder, you a merely specimen of the species?
Conversely, that picture, the light, the angles, something’s clicks. The words, the ideas, the movement of the story. Your body reacts. You save it for later. You know why. A private movement and moment. Do you value it less for it’s immediate function? Is it art or literature when you masturbate over it? Are they human or porn in that moment of pleasure? Do you read the words or stare intently at the picture, or use it just to get you going? Do you return to favorite pieces?
When I write something with an erotic scene in it, one of my goals is to get the reader hot and bothered.  If the scene doesn’t evoke some sort of reaction, then I feel like the piece failed. 
I don’t mind at all that something I’ve written might become someone’s masturbation fodder.  What would bother me is if someone who has read my work thinks that I would act in the same way in person. For example of I met a reader at a conference, book signing, or elsewhere and they thought that since I write erotic pieces that I would act in an erotic way with them. That I would simply get into bed with them or do some of the acts I write about with them, would be annoying. 
As far as being on the other side of it. I tend to think of my fantasies as humans. It’s the connections that I find most erotic and arousing, not just the act. Anyone can go down on another person and it feels good, but it takes a connection to make that episode explosive.  
If my work gets your motor going, awesome!  If your work gets my motor going, even better!