Here's a quote directly from alexp:
"I just read the first page of Love SICK... and while it is graphic/explicit, that's the whole point. It deserves our highest rating... and perhaps, given that we have stories like this, we should have a warning in the player or something. I don't know.
The line we DON'T want to cross is getting into lacivious/lecherous material. I.e. pornography. It's a fine line.
Rated R is ok, rated X or NC-17 is not."