
he's not happy but he's also not sad. He's apathetic to it all. And the goal of a relationship does not have to in fact be a goal towards happiness, that would be naive especially given the plot. Realistically it's unrealistic how Gunchan truly doesn't mind his situation. But based on the characterization his behavior aligns with this extremely not common place situation.

I've seen you around before and I know you get touchy about the subject of consent. I honestly don't want to argue about it with you because I know it's going to be like arguing with a brick wall lol I know it's going to be a huge headache.
Gunchan isn't in a reluctant, dubious consensual relationship. He discussed it with the head. After the bite, the father told him to work under him but Gunchan decided to bargain.
Father: You want me to work on getting your attention? To say such a thing when your life is at stake.
Gunchan: There's also no guarantee that I'd live even if I do as you say.. So then wouldn't I need to do this at least to make it even?
Father: Very well. I'll let you have your way. You're the first human I've seen unaffected by domination or scent. But as I'll need to teach you about your physical reactions myself-- I will need your permission, Mr. Writer. Would you like to try it?
- Chapter 55, page 1
Hence, the sex/assimilation scene. There is no "he cannot exactly walk away from things now that he's literally being held captive by a vampire's desires". Gunchan was the one who proposed it. They are playing a game.
Look, the first bite that made him kin was against his will, but the rest that followed were purely consensual (ch58, pg 2) as mentioned above. The part where he said he couldn't stop cuz it looked like fun (ch 55, pg3) is him agreeing. Apart from the beginning of the kidnapping (where he had to get knocked out to be kidnapped) the total times they got physically violent were a total of two: Gunchan punched papa for that surprise bite (ch50, pg 5), Father choked him and Gunchan kicked him in the stomach to make him let go (ch76, pg4). There was a scene at the hotel part where he held Gunchan by the neck but no one actually got hurt.
The rest were civil conversations and the agreed mind games. During the time where Gunchan had to recover from the bullet wound Edric gave him, the father didn't visit apart from the first day. You know why? Because Gunchan pointed out that all of these (the paid hospital room, special treatment) was him trying to woo/get in Gunchan's good side. Edric and Chief mentioned how soft the father was because of him (ch70 pg6-7). Even when he wasn't there to watch over him though, he'd ask Edric for reports to check on Gunchan's health.
What about the hotel scene? Gunchan didn't mind the service. It's luxurious for a hostage (ch 54, pg6). Did the father come in repeatedly for assimilation sessions? It was never mentioned at all. Father being in a good mood after the visit with Gunchan at the hotel (ch56, pg2) might've been a hint though.
Now that choke that people seems to focus on every time. It's because of this people seem to misinterpret their relationship as violent and/or abusive... It's the meaning behind the actions they've done that's important. For example, we've got chief punching Edric when he does something stupid, just as Minhoon had smacked Hyungwoo when he went out of line.
For our side pairing--Gunchan knew the father would react violently but he provoked him anyway so he could get the answer he wanted (ch77, pg4). Whether or not the dad was fully in his mind is debate itself. One could argue that it was a knee jerk reaction. It took him a while to snap out of what he had been doing. I do agree the 'sex' afterwards came out of nowhere though. It looked like a weird mix of sexual tension in need of release from both sides. Gunchan had been anticipating the Father's return at that point.
It's been revealed that they both knew (emotions shared through kinship) that the father never really planned on killing Gunchan. Honestly, the 'mind games' aren't even that serious anymore. Gunchan's like 90% sure the dad loves him. Gunchan had deduced earlier on that the father's been wooing his ass for a while now(ch60 pg 5 and ch67 pg6), even finding it amusing that the father's doing a lot to get him to stay (ch72, pg4).
That part where Gunchan started talking about how he wanted to hear about the father's story (ch 83 pg 15), 'all for the script ofc'-- my interpretation of it is that the father's pretty frustrated since he obviously likes Gunchan but for the latter, Gunchan seemingly wants his curiosity satiated. Right now, Gunchan's just watching things unfold since he was asked by Minhoon to put his trust on him.

He could've forced himself on Gunchan with his heccin' power but he agreed to play the game so they're doing this overly complicated tango. These things are still up to debate though. We're going to hear Gunchan's actual thoughts like in 2 chapters?? Judging from the RAWs anyway. Ch 100 is the confession from Gunchan.

You do realize that’s the whole point. Gunchan was made kin against his will and what has followed suite is Gunchan making the most of the situation out of said curiosity. I never said Gunchan didn’t consent, I’m saying he consented under circumstances that already made his situation limited on his part to do anything but accept. That is dubious consent. He could consent to engage in sex but he couldn’t resist his new formed relationship with the father or all the things which followed. I personally don’t find it believable but that’s a difference of opinion not what the work presents as fact.
The father giving him that “choice” is not really a choice when the deed has already been done. If Gunchan thinks what will transpire will be “fun” that’s fine if he hadn’t already been kidnapped and been forced to turn into a kin looming over his head. What exactly is Gunchan suppose to say? No? And risk further physical repercussions? Gunchan is smart, he would never pick a choice that would impact his self preservation. Are you telling me he would have made the same arrangement if he hadn’t already been kidnapped and made into a vampire’s sole blood bank? That he finds that his two best friends are also involved in this game of mental chess as well means he can’t escape entirely unscathed and resume his normal life. Gunchan works because the author has given him the personality that he is rational and apathetic to EVERYTHING.
Gunchan doesn’t react to anything immediately he weighs the pros and cons and makes his decision through rational analysis. It’s why for instance why he has no problem telling Minhoon to break up with Kim Hyundai Woo despite their decade long friendship. Realistically Gunchan would not be so causal about the situation as we saw directly how Minhoon reacted for example. Or even how their last friend in group found out his three friends were mixed up in. Minhoon had at least more time to process things for days, weeks compared to Gunchan’s single day that progressed as quickly as it. Gunchan is Minhoon’s direct foil. Both were turned into kin against their will. Minhoon reacted in a way most would upon the discovery vampires are actually real, hesitant unsure and scared. Gunchan doesn’t have that type of personality or feelings towards the situation. All of your evidence is there but it’s a moot point to say Gunchan’s relationship with the father is consensual when their relationship is a game as you’ve said which Gunchan is the loser if it costs him his life if doesn’t handle things just right. I can appreciate Gunchan’s characterization and if he wants to engage in this current game of wills that is consensual as you’ve stated because to some extent yes he’s agreed to it. However the circumstances surrounding his introduction to this world is in fact dubious consent none the less.

Man, I knew the moment I'd come back you'd have a long reply that'll heavily disagree with me. Y'know, when you said "the thing is none of it was consensual" earlier-- I read that as "it's non-con". Now it's dubious consent, huh?
"The father giving him that “choice” is not really a choice when the deed has already been done. If Gunchan thinks what will transpire will be “fun” that’s fine if he hadn’t already been kidnapped and been forced to turn into a kin looming over his head." Really? You're gonna nitpick this? Yeah, we all know he was basically forced into this situation and he's making the most out of things, but that's besides the point because it's still consensual.
You seem to interpret it as merely as an illusion of choice. That's just you thinking the lowest of the father. He's decent enough to keep his word with Minhoon's proposal, he's doing the same for Gunchan too. That's why he asked for permission. Besides, the whole point of the game is to win Gunchan's favor. The Father is smart enough not to force anything to someone as strong minded as Gunchan. How is the he going to win any favor if he's going to do the opposite of what Gunchan wants?
Everything else apart from the whole hotel kidnapping bite scenario is consensual. I said this already. We seem to agree the beginning scenario was non-con and yet you managed to make it an argument, what the hell?
Honestly, you just seem frustrated by how unnatural he seems to react and how "realistically Gunchan wouldn't be so casual"-- no, that's just how you want him to act. The author wrote him this way. What we see is what we get. That's how he is.
Minhoon and Gunchan's circumstances are pretty similar. They were both given the bite against their will. They both had time to think about it. He was given more than a few days to process things. Gunchan said it himself, "I would like to postpone. You expect a person to agree to cooperate if you just drag them here and tell them to?" He's not going in blindly without knowing things.
He used the remainder of his time during the hotel kidnapping to stew on things. (CH 54 "I've given new gowns each day" < meaning it's been days since he's been on lockdown). He was visited by Edric so he could get a better idea of the whole vampire situation. Gunchan was the one to point out a lot of things that the vampires failed to comprehend about the bond between a kin and vampire. He didn't even stay that long since he was rescued by Minhoon and the rest.

I agree that the bite wasn’t consensual, but Gunchan was intrigued by the father even before he knew about the vampires and was bitten. After he was told about the vampires, Gunchan offered to help. I got the feeling that his offer of help was mostly due to wanting to help his friend but was also because the whole situation intrigued him especially the father (I got the feeling he was slightly disappointed that the father was the “bad guy”).
I don’t believe that Gunchan is just making the most of a bad situation. Gunchan has a curiosity that could get him killed someday and the combined intelligence that can make him a born manipulator. He is the type of guy that would push other people’s buttons just to see if their reactions match his theory of how they would respond. Giving the impression of being cold and detached from the situation like a silent observer and father vampire is the most interesting person he ever met with a few lifetimes worth of experiences. I think if he could, Gunchan would pick through father vampires experiences with a fine tooth comb not leaving a single thing unexplored. Gunchan can’t be controlled by dominance so given the chance he could just walk away (and he was given the chance when he was rescued). Yes, he got shot and ended up back in father vampire hand but he also knows that all he really needs to do is tell his friends he wants out and they will make it happen (keep in mind that Gunchan knows that one of his best friends is also the most likely able to defeat father vampire). But why would he want to leave when he is exactly where he wants to be with a front row seat to the most interesting drama. What author wouldn’t want to live in the world they create and watch there characters take on a life of there own. He is also in a key position to subtly influence both the antagonist and protagonist into the direction he wants them to go. It could be the ultimate puppet masters delight. Lucky Gunchan is more interested in watching the drama unfold with little guidance.
Before I read, i wanna know, is there sexual harrasment from an antagonist? Or an antagonist being too extra, such as an ex lover or a love rival who spreads rumor/make misunderstandings that causes lots of damages?
Pretty much, i dont like it when the antagonist is going overboard just because he wants the uke(its always the uke, very rarely that the antagonist is aiming for the seme)