Jongwoo:

Suspicious and paranoid but he wouldn't break it up or claim you can only have him as your friend. Even he knows that's insane. But he would like it... So he doesn't say anything to you but the cold wall he puts up to your friend is quite obvious. Most friendships he hears of this end with one falling in love.

Moonjo:

Even if you are a man, and so gay as you are with him, he'll still not want you hanging out with women. So no to you being friends with the opposite sex. Fuck it, not even with same gender! He wants you isolated, only his. He'll ensure that will be so.

Junghwa:

A bit of jealousy but she trusts you. Just not them. She finds it hard to believe they don't hold other motives... BUT she knows to think opposite genders can't be friends is an old mindset so she tries not to give into it. So long it doesn't turn suspicious then she's fine with it.