Taemin is fighting againts a bad illness that is threatening to end his life. He dont want his lover to worry about him, so he broke up with him. He doesnt want his lover to be worried and sad as he suffers. He wants him to continue smiling... that's the best thing he can do so far. Still, his lover has no idea about this illness. He did not try to say it to him. Only his best friends, Jonghyun and Minho knew about his condition. 

But what if his lover finds out? 

Taemin promised to protect him...

He dont want to see his lover cry...

Because he loves Jinki so much.