This just gave me a thought... imagine if they did break up and Jowoon decided to use their parents as leverage??? Like he threatens Haesoo that he’ll tell their dad and mom about what they’ve been doing. Maybe make it seem like Haesoo forced HIM to do it.
Heasoo's mom knows
I know she caught them when they were teens, but I don’t think she knows they’re still doing it.
Heeso is trying to convince her that they only interact with each other as brothers but she is very suspicious and does not believe him. Check ch34 http://www.mangago.zone/read-manga/love_or_hate_yeongha/uu/love_or_hate_yeongha-chapter-34/1/
She detest Joowon and does not want the ex-husband to find out what happened while they were living under the same roof. I wonder what will happen when Joowon's father finds out the real reason why they got a divorce.
Is this foreshadowing of Haesoo breaking up with Joowon and choosing Taekyung, and how Joowon invalidates Haesoo's break up and gets super pissed at Taekyung and tries to manipulate his way back to Haesoo (maybe through their parents or through sex?) ....it seems like it is.