So confused!

So... like WHAT THE FUCK IS HAPPENING?! Why does Chamin act like he doesn't remember having sex with Dowan? Also, I honestly feel so bad for Dowan! It's like he has consistently been there for Chamin through his break up, literally gave up their day trip to drive him to see Sena, comforted him after he broke up with her, always put him first. Loved him from afar, then helped him get over the break up, and for what?! To get mixed signals and made to feel like he was fucking up!
(╯°Д °)╯╧╧