I am not disagreeing at all, just wanted to mention that "too much sex scenes, not enough story" is a refreshing reversal of some other comments in some threads along the lines of "stop story, my head hurts from reading, gimme fucky fucky nao!"
The story is about an app that lets the characters explore fetishes they might not consider otherwise. Apart from the fact that the question what constitutes a "hard" fetish is pretty subjective, the story is about getting acquainted with stuff, not turning it up to 11. (Of course the meta is turned up to 11) Also, with multiple fetishes going on in parallel it is unlikely that somebody will get one specific completely satisfied.