I think it was cus they where forced to be married. By their parents. So they grew to resent each other.
Oh yeah! There's that kinda reason. There are lots of scenarios coming to my mind when thinking bout their character:
1. If they so happen to know each other carefully, they might have also fallen in love, still be together and have more kids. They have good genes anyway.
2. Taesung's Dad happens to be gay or attracted to someone but happens to be a guy. He might have that someone from his past and might be scared to confess and that he's not yet open for homosexuality. So he has no choice but to conform to his parents' decision just to prove himself that he is normal. But then that also didn't work out at the end.
3. Taesung's Dad has a girl he actually loved in the past but their parents opposed to them due to difference on economic level. That's why he was forced to marry someone he doesn't love. And he doesn't know that the love he and the girl shared in the past might have bear fruit -- and that is where that red-haired guy were coming in.
Every scenario were good!!! Hope to have one of these on their panels one day.
Yeah. Those are good ideas... I would love to read those as a fanfic....
Hahahaha!!! This update got me like falling out from a chair. Taesung's parents are hilarious! They're so much alike. I wondered for a moment there 'why did they divorced?' again...?? #ep109