Those are the endings in Emily is away
If you decide to talk to Emily in chapter 4, where she talks to you about the events that happened during her visit, in chapter 5, you will have the standard ending like she got back with Brad/Travis (depending on if you went to the party in chapter 1 or not) and if you try to drag on the conversation, you will end with three goodbyes in the choice.
This ending is when you invest a lot into her and obviously would be seen as a bad ending.
Then, you wanna be a jerk and decide to take revenge on her. You want to abuse her at her most vulnerable moment, it means at chapter 3, when she suggests to visit you. Let her come (not only as friends), be a gentleman and tell her that you have alcohol. Then, on chapter 4, you don't talk to her! You can imagine what happened during your visit and you're kinda happy with Emma, don't let that drama queen turn your head around, make an excuse or something.
And finally, on chapter 5, when you try to talk to her, she'll just make the same excuse to you and the game ends.
So, to sum up, you scored something with Emily, you are with Emma, game over, best ending.