Erotica is usually boring. The author aptly escapes this charge by using 1) short chapters, 2) multiple voices. At times the story line droned on, after all, sex by any other name is still sex, although this writer spiced the story frequently with technique variables to make a sex Ed. prof blush. The predictable plot moved along at a solid pace. My opinion, the "Gang bang" chapter was just pornographic and vulgar.
Read the story now
Stylewise, 1st. person, present tense is at best hard. And, the writer slipped a number of times into 3rd. person - for whole chapters, but unfortunately also for certain paragraphs mid chapter.
Technical skills overall were okay, although a red pencil is needed to eliminate what appear to be typos.
I hope these notes are helpful.