Father's just all talk imo. He doesn't seem to want to kill Gunchan at this point anymore. He's like half tsun about it, especially when his sons pointed out the possessive/obsessive smell coming from Gunchan.
Since, y'know, he can't really use 'domination' on Gunchan because the latter can barely feel it. He's like, what does it take for you to stay with me? The pairing still has a lot more chapters that'll feature them. You might get what you want U:
No, don't kill him. We want that Father and Shim Gunchan content. (=・ω・=)
And I really want to see Gunchan be the one to make the that Father suffer.