I like it so far (halfway through part 4 now) but I've got some problems with the way you're describing Valerie. You are describing her as not attractive because she's fat, and as if she is less of a person because of this. That kind of stuff offends me even though the rest of the story is interesting and well written.

The story is told from David's point of view. He is indeed not very attracted to Valerie because of her weight, so the writing reflects this. However, Amber knows this too, which is one of the reasons she chose to "rent" him to Valerie as his ultimate training.

Personally, I find all types and shapes of women attractive. No offense meant.