I know porn and erotica are sometimes about pushing the limit or entertaining taboo fantasies one wouldn't seek or play out in real life, but I think I'm in the minority when I say I don't mind the step-relation or "by marriage" types of stories (and maybe this is porn's fault), if done well.
I know some people see it as a cop-out or loophole, but I feel like it's less about the "incest" aspect of it and more about the social taboo b/c the characters are supposed to see each other as family and off-limits, but in reality aren't. [...]
Does this mean I'd fight for these types of stories staying in the Incest category versus a generic taboo or other category? No, but I think there's a place for the step-relation or "by marriage" type stories where it's more about the "our family or town wouldn't really understand" or there's a long-term relationship there that feels very familial versus the "Oh no, we can't! You're my step-[person]. It's so wrong!" types of setups often seen in porn.
If you're writing an incest story you have to invest in the taboo, or you shouldn't bother with it at all. When a story has its protagonist coming onto a family member and that family member instantly goes "oh wow yes I've always thought you were super-hot too let's fuck literally immediately!!", I feel like that's missing the whole
point of including a deep taboo like incest in your story.
I have a well-publicized dislike of isekai-type "literal Mary Sue gets transported to another world where <insert author's taboo fetish here> is totally normal, thus erasing the tabooness and making the story utterly bland" stories, and this is just another form of it. You should never ever minimize your taboos; you should
indulge in them. Never write clinically or matter-of-factly: emphasize the taboo of your incest plot, the filthiness of your watersports scenes, the throat noise of your face fucks, the helplessness inflicted by your bondage! Submerge yourself and your reader in the thoughts, emotions, experiences, and sensations that your characters are having. Make it visceral, even a little exaggerated, and your sex scenes will be far, far better for it.
So in that light, I think step/in-law incest totally fits in the incest category... as long as you do emphasize the taboo aspect. After all, even though your sister-in-law and step-father aren't blood-related to you, having sex with them is still heavily frowned upon. So have them struggle with their attraction. Have them hide it from a world that won't understand their love and/or lust. Have them
fail at one or both, and deal with the consequences (but sexily, at least in part). As long as it deals with all the things that blood-incest deals with, it absolutely counts as incest, in my opinion.
I am slightly amused at the loopholes. Either write incest porn for real, or don't but using "loop holes" is just silly.
Isn't silliness the whole point of the thread?
...I say, seconds after writing a whole essay on the merits of (step-)incest.
I'm just amused when there are cases that are 100% loophole abuse because someone thinks that slapping "step-" before incest is just the easy way to make a film more acceptable.
"Incest" plots are also just incredibly cheap to do. Put a guy and a girl on a couch. He calls her 'sis' exactly once, then fishes out his magnum dong. Le gasp, step-bro wat u doin. Boom, plot done, on to the sex.