Leo is not owed an explanation by his victim he can open his mouth too and ask what he did wrong. For someone who wanted this relationship so badly he was just too stupid and proud to pull his own weight. Let him wait for phonecalls that will never come, listen to all the heartbreak songs and run in the rain until he gets some sense. Or he can just get another JJ 2.0 cz he's such a catch.
JJ literally told Leo. It was phrased as a question (Did you ever see me as your boyfriend?) but that doesn't make it any less a statement about how JJ feels. He's in doubt about the status of their relationship and Leo is oblivious to it. He's being infatlized by being excused so much, he's a grown man as much as JJ is. It's not cute to tell your boyfriend that you don't wanna go on a trip with him bc of not wanting to be recognized only to receive a phone call five minutes later and run off to an impromptu bar hangout where you will be recognized. It's not cute to sexually use your boyfriend and leave him hanging. It's not cute to only expect your boyfriend to be the bigger person - by being the only mature one and the only one not allowed to feel hurt or to have accusations thrown at him about sleeping with some other guy when they could just be friends casually/professionally talking. JJ does and will have to apologize about the warehouse assault, but that doesn't erase the fact that before and after Leo was selfish in their relationship. ┑( ̄Д  ̄)┍
Hey wait. Don't argue lol. We all have our own enterpratations on this. And don't invalidate one's feelings because the other party looks more ptitiful than the other or vice versa. As I've said before we really don't know what happend in their 5-yr relationship. This manhwa shows more of Leo's POV not of JJ's.
JJ just got tired of everything and chosen to give up in their relationship. He hoped that Leo will change over time but it didn't happen. JJ is in the process of moving on and moving forward while Leo is still stuck in the acceptance process. The break up and moving on is devasting experience. The acceptance process is the hardest part of moving on. You know all the memories you've made together will just remain memories and imagining that person will no longer with you anymore and might be with someone else making good new memories is so painful and feel like you will go crazy. And 5 years is no joke bro.
Everyone deserves a closure/ an honest reason as to why would a person chose not to stay in the relationship anymore. For the other person to asses his/her action and ask for forgiveness for everything that has done and might be to easy for them to accept what they couldn't change and choose to move on instead.