SPOILER!(〜 ̄△ ̄)〜
They kissed for few sec but kangjin seems to be back to his senses, he somehow feels uncomfortable and avoid the kiss after that.. they talk bout something i guess i cant read korean but jun (seme) looks so bothered (or hurts) by it and after work he looks depressed bc of it then suddenly he get love confession from the blonde dude.. again idk what they r saying but in between their conversation he suddenly remember bout the kiss rejection (with kangjin) and then he accepeted the blonde dude confession and kiss him (istg he look dead as hell and didnt look happy at all)
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I guess this is spoiler anyway the situation right now is that kangjin still has a space in his heart for jun, same goes to jun. But it seems like when kanjin planned to revenge jun by approach him, kanjin felt like it was hopeless and failed (maybe he thought jun is ready to have a new lover) after kangjin saw that pic (jun kissed the blond dude) so he decided to just move on even move in with his new lover (like when he in his seme house he doesnt even remember jun anymore). On the other hand after kanjin rejected jun kiss, it feels like he accepted that blonde out of depression (he stil hurts bout that kiss) and even tho he tried to move one he still searching for kangjin in blonde dude, when he heard that kangjin move in with his new lover i guess thats when the hopelessness and guilt kick him hard at that point (he realize that he still love him but its already too late even to get him back). In conclusion they both tried to move on and knew it was hopeless to be together again. This is not the end tho i just read tje raw and what i can concluded and i could be wrong.