Pretty much in character tbf, yoonseo alrd feel something for jihan since they were inside dungeon, no, even since the auction incident, to the point he thought "maybe it's okay if it's jihan." He's opening himself bit by bit, never experienced a romance i think it's logical for him to be unguarded when someone he felt something with declared that he's their type.
Wdym forced lol on the contrary i think theyre developing naturally i can literally see the progress. There were so many sparks since they first met, like when yoonseo shows how touched he is when he realized how genuinely kind jihan is when he hugged the bomb to shield everyone from the explosion during the weapon auction.
why do you want him to act completely indifferent when he’s not? the reason why he’s guarded is not bc of his personality it’s bc he had to see all of his friends die actually I think that’s his actual personality coming out when he’s with jihan
I'm sorry but like this is too forced. Yoonseo's reaction to jihan when he said he is his type was too out of character in my opinion... Would've been better If yooneo was genuinely unbothered cause that would be a more better reaction to me. The romance out of nowhere was just wierd