This story is VERY clever.
The author has interleaved the stroke story with lines as if taken from a nature documentary. This mechanism is not as intrusive as one might think, and it makes for a damn good story. So technically I give it very high marks.
The plot is pretty standard stuff, although a few twists are needed to give the protagonists their opportunities. Nothing requiring suspension of disbelief though, just acceptance of circumstance. And a reasonable amount of tension: will "this or that" happen, or will it not?
As a stroke story it's damn good. Hot steamy sex, lust for its own sake.
Certainly it appealed to me - I wanted to see where the author was going with his technique, and left satisfied. I'll look up more Les Lumens stories now, and that's a good recommendation.