Well, all her siblings sure give me the vibes of being jerks because they weren't there for her in dire moments, as shown in the chapter. Black Lavender
its because MY(strong emphasis) baby Jinhyun feels like he would be running away if he leaves the playing field. I think this has been reiterated by MY(strong emphasis here, again) baby Jinhyun many times.
What kind of ending was that☹ So unsatisfied