I really don't think that chungho wants to be top, but if he wants to I don't really have a problem with that. I just think that he has a problem with his lack of involvement in the decision process when they have sex. His inability to say no and the fact that Jun is purposely ignoring that and doing whatever he wants are the main problem.
I love them but I really want to punch them right now, especially Jun if I'm being honest ╥﹏╥
I'm just praying that this misunderstanding is gonna act like the little push they needed to finally confess their feelings for each other, because I'm panicking hard right now, everything was going so well :(
This may contain spoilers
I think he may be feeling like that because he wanted to stop but felt like he couldn't...? Or because he noticed how the mood was off and they didn't do it for the right reasons. Also I feel like Jun was in fact kinda angry at him so that's why he was testing his limits and kinda turning a blind eye to what chun was saying or how he was acting, even thought he noticed that chun was kinda uncomfortable and unprepared. I don't now, I personally didn't like how it went down, it was forced and uncomfortable in my opinion. They need to learn how to communicate those feelings and of course to NEVER take out anger or insecurity with sex, that's just a big nono
I just hope the author is using this to talk about consent and the feelings that may arise while having sex and not just using this for pure drama, but to be honest I'm having my doubts. Anyway, lets wait and see :p