
Probably close proximity mixed with the fact that he is bonded. Like as he acted nice it eventually turned into reality instead of acting. Pluse the bond made him instinctively crave chiyoung both physically and mentally and he could only deny it for so long before eventually actually falling for him. Also he only didn’t like Chiyoung just because he was a guy not because of his personality or anything so over time he saw more of his personality and feelings grew.

Fr and it was all his trauma of being taken advantage of from male guides growing up, so can't blame him too much. ...there is a bunch of other stuff that didnt make sense, like why was the chiyoung just working in a bar if he was so important and why dont they just tell each other whats on their mind. Chiyiung i kinda understand.
But these stories about two people being on complete opposite mindsets of each other all the time is getting too frustrating for me.
Hate the colonel all you want but comparing him to the other grape manhwa, he's 100% better than most of them. Although he's a douchebag