I thought people might ask why Baekhyun left. Well here's an explanation so hopefully it makes things more clear :3

The whole time, Chanyeol is finally helping Baekhyun open up to him, slowly. Chanyeol never asks Baekhyun why he’s so precise with his routine, and he doesn’t pry anything out of him.  He just lets Baekhyun open up to him at his own pace, and lets their relationship move along at a decent pace. So when Baekhyun forgets to order his Americano, it shows that he’s starting to move away from that strict routine because of Chanyeol.

When Chanyeol mentions Baekhyun’s reasons for letting Chanyeol sit by him, Baekhyun gets sensitive. Chanyeol let it go, because it wasn’t the right time for Baekhyun to be open. He asked it too soon, but since he let it go, things were still okay.

But then, when he asks about going to an Italian place, he explodes on Baekhyun, which causes Baek to retreat again back into his own little comfortable world. Baekhyun is afraid of commitment and change and because Chanyeol is offering something that would include both, Baekhyun doesn’t want to do it. Chanyeol should’ve let it go, and let it happen on Baekhyun’s time, but he doesn’t, which is what kind of screws everything up.

When Baekhyun says “No Chanyeol, you make it difficult,” it’s because Baekhyun is so used to his daily routine and Chanyeol is making it difficult to keep up with those things Baekhyun wants to keep constant.

If Chanyeol were to understand this, he could prevent Baekhyun from leaving, but he doesn’t.

Chanyeol then sits in Baekhyun’s seat, which is kind of the last straw - it breaks Baekhyun. Then Chanyeol tells him he loves him, and Baekhyun, though he himself recognizes that the love is returned, can’t take that much in one day. “You’re not helping me though,” is the truth. Chanyeol needs to approach Baekhyun carefully, not suddenly, and because he fails to do so, he never gets to become closer with Baekhyun. Baek ultimately leaves Chanyeol, and ironically changes everything himself by never returning to Cafe Reve.

Baekhyun says Chanyeol “made it easy this time” because before, while Chanyeol took it easy with baekhyun, now he is being too brash and sudden, which makes it easy for Baekhyun to leave.

The reason he leaves is because he’s controlling it. He wants to be alone again, so he doesn’t have to change his routine without his consent.

Chanyeol though, is already too attached. He waits for Baekhyun, day after day, which shows that he himself has kind of become a "Byun Baekhyun", obsessed with his own routine, waiting for Baekhyun to come make things the way they used to be again.

It's kind of a sad ending; they're both alone and ocd...
but yeah ;~;

I hope this clears some things up for you guys...
I know it's a bit stretched but... yeah sorry if this disappoints you.

basically baekhyun left so that he wouldn't be swayed by Chanyeol anymore.