MC is kinda in denial about amane and saku. He always acts like he is uncomfortable but gets a boner each time. Of course he is on board with doing miko
The ntr was just bait, this story is more about swapping and the descent into debauchery.
She looked gigantic in that double page. Not just the fat way but like she a lot taller than him too . Web mangas only release raws in volume form or if you are willing to pay per chapter. Iirc the pages are censored in the following chapters so waiting for the tank might be best.
There you have it, cute penis beats big penis every time.
Also think people are missing the note that saku actually hasn't tried steal his girl and has actually been pushing for mc and his girl. amane is just easily swooned by his hotness.