So long as it falls under the PG-13 rating, you can post it here. If it doesn't, you can post it elsewhere (like google docs) and link it here (in the Writer's Guild subforum) with a warning accompanying the link.
I do not believe you will find it terribly difficult to locate mature people to peruse your writing here.
I do not believe you will find it terribly difficult to locate mature people to peruse your writing here.