A quick note from the translator:
We're aware of an extra page in this doujin set from the author's Twitter that we did not translate for this project. (Viewable here https://twitter.com/bon_feather/status/941268636949344256). Please note that this page was left out on purpose, as it details the plot of the doujin as a form of content warning. We therefore felt it would be redundant to put into this release.
Seems I opened a can of worms with this.
The post says "NTR," yes, but please note the Japanese "netoru" simply means "to steal another's lover," and doesn't necessarily refer to the nastier things English speakers associate with the term. In the context of this page, it's simply a warning about how this story contains a cheating element.