“Episodic serial” not sure if it’s exactly the right word. For example, my Jeff story, which started off as backstory to explain the swimming instructor to the main protagonist, has generally become a series of “episodes”. So aside from episode one, which is the “inciting incident” to put Jeff into his general living situation, the rest chronicle his development over time with a series of snapshots. An episode shows the danger that’s generally pressing inward. Another shows some danger he can bring to himself (hypothermia). On occasion, two or more parters with a mini-ark when it gets a bit more involved.
There *is* an example on AO3 that I’m aware of, called “The Breeding Ground”, which (according to the summary) is an anthology of Harry Potter sleeping around, with each of the 2,000 chapters featuring a different woman/lady (there’s crossovers to a myriad of other fandoms). (It’s a tad over 3M words...)
So, if you’re aiming for the smut circle … you could scatter a common theme at the start of each chapter (a group conversation, part of an orgy) with the BOLD words of “A year earlier...” I mean, once the audience is used to the format, it might work.