"she has gotten upset with him for doing less"...?Jung's ex-girlfriend repeatedly tried to kiss him and had keys to his apartment. Sook hee's ex-boyfriend took her out to public spaces and asked her out in ways that it was difficult for a Korean woman to refuse (by playing the "repayment" card).
I don't know why people expect women to account to their respective partners for every last minute of their time, nor why men are sympathetic for being jealous. Jealous women are called bitches and told they need to have more trust.
Personally I find these interactions more real than the extended misunderstandings that rely on deus-ex-machina to keep not getting cleared up naturally. I think Jung's jealousy is handled well - it's present, and he has some reason, but so far he hasn't done anything outrageous about it. That doesn't make him a saint, it makes him what we should expect out of both sides of a relationship. Except maybe the violent arm grabs, there's got to be a better way to do that, but it appears to be expected in these genres.
Anyway, thanks benefactor!