I got the Keith and Tenebris NSFW endings, for Keith, you need to show you are jealous of the waitress giving her number to Keith by choosing the option of "enrage" after she gives him her number and make sure you have positive interactions with both Keith and Tenebris.
For Tenebris, you have to be nice to Tenebris, talk to your co-worker Jacob, go on a date with Keith, you ask him to switch with Tenebris, once you two leave, you ask to see Tenebris again. Once you hear noises from outside, you need to go out of your apartment to check it out, now if you do it correctly, instead of having only one option to run and get the police, you get an option to stay. Once Tenebris is in your apartment, you click "Take it further" and well you get NSFW ending
Hope this helped