Moved to correct forum area
I actually like this idea tbh. Almost like an "anything goes" area. We don't have to restrict it or enforce it, just make it so that only registered forum members can enter the forum area (IE, public can't see it, it's not returned in google search results etc). I'd wager 99% of everyone on the site is 18+, so I'm not bothered by that and we can have a warning in the forum description to say it contains potentially sexually explicit threads.
I'm a supporter. I'll talk to the others.