That is not the Tenebris route, that is a bad end with a nsfw scene. Majority of his regular nsfw scenes are in Date 5. The guide for it is here, among the downloadable files.
The guide for surviving the end of Date 4 is linked in linked in my last post here. I will also link it below:
https://www.tumblr.com/dualityvn/787976877184827392/date-5-guide?source=share