I mean, I get it that 1x1 is that pornography magazine that you read and then never read it again. But, I'm here to make a suggestion. It was made by Prince and I'm putting it in the  suggestion forum. He said this: 

"If I were to make a suggestion here, it would be to draw a definite line for mature content in regular 1x1's and create another forum similar to it for the specific purpose of allowing higher levels of mature content..."

I think it's basic, put the 18+ 1x1 or RPs into another forum. Of course, it will need rules and a warning message. But, in all, I think that this is a good idea.