Unless he hid his feelings until he couldn't anymore, because jealousy or whatever.
but still that transition feels so off and out of nowhere?? Like daiki really didnt care... and even if he did he did a damn good job of hiding it so suddenly openly showing how he feels is very confusing ??? since there's no flow behind it im very confused with the change
I agree, but there's no good reasoning behind it. Unless, Daiki is just making a show of their relationship, or just taking advantage of the MC because he's aware of his feelings for him. But, I think the jealousy reason is the most likely.
Why is he clingy all of a sudden? And jealous? He was indifferent just a few chapters ago.