How long has it been since you've seen Oppa, Ji-ae? Less than a week but it seems like a long time to you? That's because you've been spending your honeymoon in your own fantasy world with farmer boy.
Could you have really misunderstood the relationship between those two…? Duh! Since you haven't given Oppa a chance to explain, and you won't believe him anyway, what does it matter? But there's no doubt that everyone else can plainly see what type of relationship you're developing with farmer boy: the type of relationship you should be having with your "husband" while on your "honeymoon." But, no, you clearly made up your mind as soon as you met the farmer boy that you'd rather spend you honeymoon with him than with your husband. When he showed up at the farm, you even told your husband to leave so you could be alone with your new lover.
I can't blame Ki-bum in the least for getting pissed. Not only at his "wife," but also at farmer boy. To watch your wife spending your "honeymoon" flirting and having a grand old time with another man, while at the same time ignoring you, is just too much. If it was solely a matter of revenge for what she perceived to be cheating, then that would be one thing, but it's not. She's infatuated, if not falling in love with farmer boy, and simply wants to spend her "honeymoon" with him.
Ironic that she should still be pissed at her husband when she, herself, has been far less faithful to him than she thinks he was with her.