I Love It When Sci-fi And Fantasy Worldbuilding Is Clearly Structured Entirely To Explain The Omnipresence

I love it when sci-fi and fantasy worldbuilding is clearly structured entirely to explain the omnipresence of the author's weird kink, but with every subsequent instalment the author is drawn almost against their will into increasingly abstruse worldbuilding based on that initial setup. Like, chapter one will be "so there's this civilisation of big tiddy mushroom girls who all sprout foot-long boners whenever it rains, right?", and by chapter five it's like: "Actually, while they may look like big tiddy mushroom girls, owing to their fungoid genetics they really have twelve distinct biological sexes, with any given individual being reproductively compatible with a more or less random subset of exactly five of the remaining eleven; here's an extended sub-plot about how this informs their society's inheritance laws. What? Yes, we'll get back to the sex in a moment – first we have to discuss how agnatic primogeniture operates in a society with duodenary gender."