I don’t get why doesn’t Hwa’s dad like him?

Because he's just like him, plus he's pretty indifferent to anyone but his "wife."

But it’s his SON! (￣ε(#￣)Σ

Confirmed with someone that read the korean ver that it's a slight miscommunication (although Bin's love probably does go like Gok > Hwa > everyone else), b/c in the korean ver it was quite vague but he was actually referring to the unborn babies aka his future grandchildren.

I think it's the author's way of showing that Bin is extremely protective of his own family. It's not that he doesn't care about his future grandchildren b/c I'm sure he will when the time comes (remember this is what happened when Gok was pregnant too!) but those he already loves he will defend to the end.

thank you for clarifying it. i was really sad and worries that Bin doesn't care about his son.

Ooh now I get it.
Thx for explaining (⌒▽⌒)