The way I see it, there are two types of erotic fiction: stories about sex and stories that include sex. This post is not intended to be a condemnation in any way! Each has its pros and cons. Just like in real life, sometimes you want to make love and sometimes you just want to fuck. One isn't better than the other, they're just different and each has its place.
I think it's helpful for the reader to know when they crack the spine (or open the file) what they are getting. Blue Moon House is a story about sex. The plot is driven by sex. There is still a good story in there, but it can't be told without the sex.
I recently reviews the first book of the Resistance, The Arrangement, on Good Reads. That was a story with sex. Although sex did drive part of the plot, with a lot of work and the magic of 'fade to black' it could be told at a PG rating. I'm glad it's not! Like I said, not judging here. The sex was great, it enlightened us on the characters and their relationship, and well, it was just damn hot. The story would have been less without it, but it would still be complete. 
