What was that dinner about, that Eun-ho went to so reluctantly? (I looked up her name on Korean Wiz) www.koreanwiz.org/at/drama-aloneinlove.html She looked business-like, in a black suit, didn't she, not like a date. She almost didn't go inside the gate, after she saw what a big house it was. "Why do you dress like this if you're so rich" was more or less her comment to Jin-wook (he's 26 to her 28, that's not such a big difference after all).
What did his father say after she left? I missed it. sigh. Is she supposed to help the father's hotel do better with their gym?
she is being pursued/stalked by the person she went to dinner with. She had already decided not to take him up on his dinner invitation when she got pissed off at her ex husband and decided to make him jealous by going to dinner at this guys house. Since the guy always dressed casually she was surprised that his parents house expensive. I think the father saw the dynamics between the couple and could tell that they didn't look particularly romantic and therefore concluded that his son was just trying to be a contrarian to his father again.