Choose to be friends at library
Don't help Josy with her dad
Tell Derek you no longer have feelings for them
?????
Profit
I'm not really seeing everybodies problem here. If you reject the LI then you are no longer pursuing them, who cares if they are still hung up on MC. If DPC gives another chance to get back on their path, reject them again. But the MC is now friends with all 5, 3 are in a sorority with close ties to the MC's fraternity and 1 is the sister of the only friend the MC has that he didn't want to fuck, it would be weird if they suddenly disappeared form the game.
The problem is that, even doing all of that (not helping her is a mean move considering you were the 'cause' of the problem and, if you haven't done anything with her, you should be willing to confront her father and tell him the truth to help your friend, but ok), the MC still thinks in Josy as a love interest. He's still having doubts in his inner thoughts. Is terribly similar to what happened with Megan in AL. You could neglect her, you could tell Liam she was not your type, yet you still kept creeping on her while sleeping, you still hugged and kissed her at home and decided to explore your feelings together (spa scene). What feelings, man?
I don't want them to dissappear from the game, I get they are important and I don't mind being friends with them, but please don't force me into situations when I'm making clear decisions against them. Also, I still don't understand all the drama. If everybody cheated with each other, is that really a problem? It just means you 3 feel attracted, there's no need to overreact like they did. Why feel betrayed when all of you have done exactly the same with the same people? It's a glorious, almost ideal situation, yet DPC decides it's a terrible thing and waits a whole episode to let us sort things out. It could have been done much earlier, even the same night Josy appeared in the dorm. I don't get it, honestly