ML role here is the husband because of the story, romance is not the main point
That's actually right. I'm on episode 11 now and no romance other than between the cheaters. I don't recall any romantic scenes between the couple, not to mention the childhood friend. They are all busy with the revenge. ^^
I don't get it if the husband is the cheater then why is he the ML instead of her childhood friend? Is there big…
I guess it is because the husband's role is indeed more significant than the childhood friend's. It is like a battle between the wife and the husband, while the childhood friend is just the wife's supporter.
I feel like watching highschoolers in a school play, LOL.
ML, FL, and her friends look sooo young like teenagers. And I don't know why the stylists seemed so eager to make them look like on fashion shows all the time. I'm still watching this though, for their good looks ^^ The storyline is interesting enough after a few boring first episodes.
Which part? Pretending to be a pig eating a tiger? LOL
It's an idiom, deliberately pretending to be a weak person (like a pig) to make the opponent (the tiger) negligent, and then take the opportunity to win the final victory (eating the tiger).
2 
I'm subbing this until someone else picks it up.
Ep. 01: https://dai.ly/k1bluUdhmzswVbyXglk
Ep. 02: https://dai.ly/k4IkwDRICvvBMhyXfTZ
I guess they will provide English subtitles.