I use a locally hosted SillyTavern frontend with an API (OpenRouter with paid credits), both for nsfw as well as the sfw applications I'd rather not use the chatGPT frontend for.
For nsfw purposes I mostly tend to use it as a collaborative writer for my personal lewd fiction with text only. Actually tends to be rather slow burn with plenty of buildup, but you can probably do whatever you like.
Whilst there are free llm models, the paid ones are certainly better. Even the ones available open source can be so heavy that it ends up being cheaper to pay per usage rather than buy the hardware and pay for electricity.
My full costs for AI sit at <10€/year. My goto fiction (both lewd and sfw) llm is LumiMaid.
Obviously a bit of work to set this up for yourself rather than ready to use online options (and text-only) but better for privacy and probably also the wallet.
Nope, neither solicited nor unsolicited.