Remember when Hyuk was avoiding him last time, and he barged into Hyuk's house and took his virginity. Hyuk you do not want that man pissed off, he might get you pregnant.
I hope we get side stories of So-yi. She works so hard, and I think she's lonely. Where are her friends? I have never seen her with any, she just bosses Byul around. She might have a meltdown in the future.
Both of their situations are getting out of hand. They need to start talking about them, otherwise their stalkers could take advantage of that.