As I mentioned in my post on Patreon, I don’t want to include explicit sexual content in the base game because some people—especially from outside here—might not want a game with this content in their library, even if it's optional or can be disabled.
Also, on Steam, if a game contains explicit sexual content (even if it can be disabled or in the game folders), it is automatically categorized as "Adult Only Sexual Content" game on the store.
Secondly, there won’t be any price inflation (and after re-reading my post, I realize I didn’t phrase this clearly).
The price of the DLC will simply complete the full game price, not add on top of it.
For example, if I estimate the full value of the game at $12, then the base game will be $10 and the DLC will be $2.
There won’t be a situation where the base game is $12 plus an extra $2–3 for the DLC.
To sum it up, there’s no extra charge because the pricing formula will be as follows: (NSFW DLC price = full game price (SFW + NSFW) – SFW game price)