Well, I suppose that 'House of Horrors' is already taken, so what else is there to call it? Where have we seen references in D&D or OotS to risqué stuff...
Playdrake?
I'm not worried about losing readers. (We're all [well, most of us are] grown up here, we can deal with horrific violence, depravity, and semi-described sex between two or more people.) I just don't want to cut up my story so people will have to go back and forth to read it.
A lot of people who read M-rated fiction aren't eighteen. It's a matter of what you're comfortable with, not of what age you are.