Positioning: write to the erotica promise, then choose a series name that signals the plot driver
Use your blurbs and series branding to answer one reader question: is the sexual journey the core plot, or is the relationship the core plot? Erotica proper works best when the dynamic itself progresses the story (for example, consent negotiation leading to a new boundary, a training plan, a ritual, a negotiation arc, a discovery arc, a power exchange that changes stakes). For marketing copy, keep your language compliant and descriptive without turning the cover or first pages into a “graphic preview.”