Responses
Jun was already consuming that drugs way before he met Jaeyoung.
He was already targeting Jaeyoung from beginning (not sure why).
Maybe he wanted to use him to experimenting the drug?
That's what was shown on the phone Jun was holding when Jaeyoung took a little peek.
Someone was asking if he already found his "happy".

im so slow with understanding this story.. was jun jealous? why did he name him after drug? why did he drug him? so many questions..