This is supposed to be a sexy book and for the most part I just did not find the sex to be sexy at all. Plus I had some serious issues with some things:
1. They go straight from anal sex to other sex without washing. Ew! That finger/penis/tongue has been in your butt, you are all getting serious bacterial infections! The first time was gross enough, but then it KEPT HAPPENING. I couldn't stop thinking about infections!
2. A penis cannot go so deep that it touches your uterus. That is physically impossible.
2a And if it touches your cervix that is really painful, not erotic at all.

I also had some issues with the story and characters but since the book is 90% sex and only 10% story, it just doesn't even feel worth getting into.