The plot leaves more questions than answers, and feels incoherent. It's trying to convey the state of society but it lacks the exposition necessary to bind it all together (i.e. the mom's origin feels vague and poorly explained, and it doesn't mesh well with the plot). Also, the time skip breaks the pacing. Easily a 3/5.
The biggest inconsistency these NTR stories have when the guy vanishes is that they never establish him keeping tabs on her when she and her husband move to another place. It's a cliche plot hole that they always leave for the reader to fill in themselves, similar to the plot holes of the Star Wars sequel trilogy. It's highly unrealistic for the guy to just show up out of the blue without establishing how he knew where she moved to. A plausible explanation would've served the story better.
Horse's dick is anatomically incorrect and the plot is a simplistic mess.
It technically is, since Page 32 starts over but with the sister drenched throughout.