Responses
Chapter 14 she says boyfriend there too.(I think) Hangyum and Hanwool talked in chapter 21. Hanwool helped with Hajin where Hangyum helps Hanwool with Sohyun.
If he did broke up Hajin to marry Sohyun, that has not happen yet.
I think Jaehee and Hajin has know each other for 3 years. Dated two years and have not seen each other for over a year.
I am a bit out of touch with the English version

When he has a wife, recently broke up with the uke like it was nothing, but it’s a yaoi so all these things are irrelevant because we need hardcore pushy semes for more drama.