Since members of the Church are normal humans (myself included), I assume that they experience arousal from certain kinds of thoughts and hypothetical scenarios about as much as the general population.
I think, however, that there is a helpful distinction most of us have failed to make, at some point, between behaviors that do not align with our values or that would be, if acted on, unhelpful in achieving certain objectives we have, and behaviors/desires that are inherently evil. For instance, having an affair would undermine the connection between a couple...BUT...the desire for the novelty of a new sexual partner and the excitement of both a new relationship and the secrecy are understandable and, though this may sound controversial, not inherently bad. Same could be said of the themes of many common fantasies (e.g. threesomes, orgies, voyeurism, exhibitionism, etc.).
I think it's useful to be able to say, "I know why we're counseled against X. It could complicate my efforts to achieve some of my highest values and goals. But finding it exciting or alluring makes a lot of sense. It's okay that things I choose to avoid doing still turn me on. That's not evil; nor am I evil for finding it appealing."
This is the purpose of still publishing stories here that are clearly based on experiences and fantasies at odds with mainstream church standards. To remind those who experience shame about what turns them on that they are not alone, even in the Church. Hopefully those who choose to sign up for access to those stories are able to receive them in that spirit and not be put off by their inclusion.